How Ambient Advertising is Uniquely Placed to Make Audiences Think

The current body of research has identified that ambient advertising has increased in use, providing advantages for both commercial marketing (Taylor, Franke and Bang, 2006), for campaigning for the social good (Hanson, interview, 15 March 2019) and for activism (Biraghi, Gambetti and Graffigna, 2015; Hanson, 2019; Nelson and Sutherland, interview, 22 February 2019). Yet, there is little empirical evidence about why audiences engage with ambient advertising and if it encourages a longer and deeper consideration of the meaning of the advert. This study compares what academics and advertising industry creatives think about engagement with participants in-field with two media interventions. The aim of this study is to assess whether audiences are prepared to engage with low-cost ambient advertising away from point-of-sale. If so, then ambient advertising can be a useful, tactical and immediate response for smaller organisations and social activists seeking to do good.


Introduction
In 2019, the Weavers Community Action Group, exasperated by the lack of response by both the council and the police, commissioned a group of street artists, the Columbia Road Cartel, to communicate the problem with drug dealing in their area. The artists created an ambient advertising campaign/street art campaign as a low cost means to engage the general public and get them to think about the issue. They changed ordinary street 'furniture' such as parking signs to 'Drug dealers only' signs and, by imitating the language of disabled parking spaces, they created a drug dealer parking space. It was a local response to draw attention to drug dealing and was a call to action for the police. The campaign gained considerable earned media through national press and the BBC and it achieved its aims: to stop drug dealing on their streets.
Over the last two decades, there has been an explosion of many such forms of alternative out-of-home advertising and experiences in our public spaces (Rosengren, Modig and Dahlén, 2015). Ambient advertising is one of these alternative forms, deliberately placed where audiences go about their everyday lives and practices rather than in demarcated advertising sites. Sorrentino, M. (2020). How Ambient Advertising is Uniquely Placed to Make Audiences Think. Westminster Papers in Communication and Culture, 15(2), 95-111. DOI: https://doi.org/10.16997/wpcc.346 It playfully and imaginatively uses or places objects in everyday spaces to communicate a message on behalf of brands or organisations (Gambetti, 2010;Krautsack, 2008;Luxton and Drummond, 2000;Moor, 2003).
Similar to guerrilla marketing, it is a low-cost tool that can be afforded by smaller companies or institutions at a local level, not just by multinationals or large charitable bodies (Hutter and Hoffman, 2011;Jurca and Madlberger, 2015;Luxton and Drummond, 2000), allowing smaller businesses to raise awareness of their brand (Gambetti, 2010). A guerrilla marketing campaign can use ambient advertising as one of its modes of communication.
A number of factors have influenced this increase in alternative out-of-home advertising. From the perspective of an advertising creative, it is an exciting mode of communication: 'Everyone wants to get an ambient ad out' (Daltry, interview, 5 July 2019). It is not a fixed format. Ambient advertising in particular can be anything; small, large, painted, constructed, transformative. It provides an alternative to cluttered advertising environments: ' digital is now oversaturated so people are moving into street stuff, trying to spark joy' (Hanson, interview, 15 March 2019). While it can 'be incredibly effective, it doesn't lend itself to measurement which gives it a certain [creative] freedom' (Tindall, interview, 10 October 2019). In addition, the effectiveness of guerrilla marketing, including ambient advertising, is well recognised 'in terms of the ratio of costs and benefits' (Hutter and Hoffman 2011, 42).
From the client's perspective, with an eye to audience behaviour, there are a number of persuasive arguments for being more open to alternative out-of-home advertising. Firstly, audiences respond to such experiences as part of the 'hedonistic aspect of consumption' (Gambetti, 2010, p. 3). Secondly, clients have noticed that their preferred audience -the hardto-target 18-35 demographic (Eberstadt, 2000) -have changed their media habits and are increasingly difficult to target through mass media. Thirdly, as audiences we are more likely to be out of our homes as a normal part of our day: 'We live in one place, work in another, play football in another' (Cresswell, 2015, 36).
Together these form a powerful case to use alternative out-of-home ambient advertising. Envisioning this form of advertising as an audience experience and an entertainment has allowed ambient adverts not simply to be conceived as a point-of-sale consumer trigger (Shankar and Horton, 1999), but rather as a way to engage an audience at a variety of touchpoints (Gambetti, 2010). Whilst there is no doubt much alternative out-of-home advertising is created for product promotion, there is also a lot of work created for good causes and for social awareness. This ranges from the 16-foot sculptural installation Lungs for the brand Eon by Engine to the What's in Your Wash stunt ambient advert by Hubbub.
Site is an integral part of an ambient advert and it is this quality which requires ambient advertising to be studied in situ. However, while many researchers have called for fieldwork (see Abdul-Razzaq, Ozanne and Fortin, 2009;Bennett, Kottasz and Koudelova, 2000;Gambetti and Schultz, 2015;Karimova, 2014;Rosengren, Modig and Dahlén, 2015;Yuen, 2017), few have done it. As a former advertising creative, my instinct was to go out and conduct fieldwork, interview advertising creatives, and work with participant researchers as they take a physical journey past an ambient advert.
This paper is based on that fieldwork. It allows me to compare the views of academics and advertising creatives with the actions of participants to investigate engagement. I will show why audiences engage with ambient advertising; if they are prepared to engage with ambient advertising far from a point of sale; if they will engage with a low-cost form of ambient advertising; and if the ambient advert causes them to think about the message. The reason for doing this is to propose ambient advertising as an effective, tactical and immediate response for smaller organisations and social activists seeking to do good. Jurca and Madlberger (2015) outlined the four characteristics that ambient advertising uses to break through the schema we develop to filter out the routine or unimportant: creativity, unexpectedness, engagement and subtlety. Subtlety, in this instance, means that rather than using overt messaging, the advert is created using elements from the environment in a relevant way. This requires the audience to decode it. Building on Wang (2006), they characterise engagement and subtlety as a trigger for cognitive processing, enhancing 'involvement and relevance ' (2015, 55). The use of objects or aspects of our everyday places is also observed by Rosengren, Modig and Dahlén who argue that using relevant contextual elements lends greater ' advertising value' to audiences (2014,21). This relationship or ' contextual fit' (Yuen, 2017) between a relevant medium and idea is supported by Micael Dahlén (Dahlén 2005;Dahlén and Edenius, 2007;Dahlén and Rosengren, 2016) whose body of work demonstrates the communicative power of the medium. The attributes of creativity -(an unusual work) and unexpectedness (an atypical place) -attract our attention. These criteria directly reference the original definition of ambient advertising set down by Luxton and Drummond (2000). These authors defined ambient advertising as an unusual execution in an unusual location. They had initially required the execution to be the first of its kind but withdrew this stipulation later. Jurca and Madlberger (2015) further conclude that these two attributes create higher schema incongruity, raising the likelihood that we will pay attention.

Ambient advertising in context
Unusual executions in an unusual location point to street art and site-specific installation. Stefania Borghini et al (2010) observed a decade ago that ambient advertising and street art share multiple similarities conceptually, artistically, and in respect of audience engagement. While street art was more committed to political resistance and critique of brands, much of the work looked the same with many of the street artists producing work for branded charitable organisations. Both street art and commercial ambient executions hijacked signs in place, decontextualizing them to give them new meanings. The Drug Dealers Only ambient adverts by the Columbia Road Cartel exemplify this approach. Borghini et al (2010) found that street artists used intimacy and humour, often irony that rewarded audiences for decoding it. Ambient advertising is often, but not always, created in collaboration with street artists.
Creative team Ant Nelson and Mike Sutherland from adam&eveDDB London created an award-winning ambient stunt for Calm entitled Project84. They collaborated with street artist, Mark Jenkins, to create life size sculptures of the eighty-four men that lose their lives to suicide each week. They placed the work on the ITV tower which situated the message of isolation and jeopardy through height. Access to the ITV tower was fortuitous as ITV were screening a programme about male suicide. There was a dual-marketing purpose in allowing the charity and adam&eveDDB onto their privately-owned space. The advert hadn't been conceived with the tower in mind, but it added to audience engagement, something that they were able to measure in social media shares.
Rosella Gambetti (2010, 35) positions engagement with ambient advertising in the realm of experiential marketing. She outlines how the combination of an enlarged youth market and the breadth of available leisure activities 'have emphasized the importance of the concept of entertainment' in both consumer behaviour and branding strategies. Audiences engage with ambient advertising on either a sensory, cognitive, affective, behavioural or relational level -or a combination of the aforementioned. Ambient advertising transcends ordinary advertising by engaging experientially on multiple levels and being considered as much entertainment as persuasion. Dahlén and Edenius (2007) show that if one uses nontraditional advertising media and formats, people don't think anyone is trying to persuade them, or sell them anything, so they are more likely to respond favourably towards the brand.
Unexpected stimulus, such as an ambient advert, requires more interaction and deeper processing from the viewer in order to make sense of it (Jurca and Madlberger, 2015) and this increases engagement again (Yuen, 2017). Katharina Hutter (2015) noted that there is little research that proves empirically that passers-by would engage with ambient advertising, naming Dahlén and colleagues work as noticeable exceptions. This sparsity in investigation prompted her own research and has been a prompt for this research. Her empirical study conducted with Stefan Hoffman investigate the effect of surprise (Hutter & Hoffmann, 2014) and also demonstrate that audiences are prepared to interact with low cost ambient advertising. While Hutter and Hoffman's oversized shoe box had certain production values and cost associations, placing both shoes on the floor and footprints on the floor had minimal cost implications. Luxton and Drummond (2000) characterised ambient marketing as an additional mode or form that extends and emphasises an existing campaign idea rather than acting as a persuasive call to action. Gambetti went further to suggest that ambient advertising is no longer expected to trigger purchases. All three of Hutter and Hoffman's experiments were point-ofsale, positioned directly outside a shop to track effectiveness. To the best of my knowledge, only two studies have created ambient adverts and placed them in environments away from a point of sale (Abdul-Razzaq, Ozanne and Fortin 2009;Turk, Newing and Newton, 2006). The focus of both studies was efficiency of messaging; collated through response to a call to action in the first instance (Abdul-Razzaq, Ozanne and Fortin 2009), and advertising recall identified in a questionnaire in the second (Turk, Newing and Newton 2006). Neither tracked the reasons for engagement.
The current literature broadly coalesces around the idea that ambient engages audiences when it makes use of elements from the environment unexpectedly both in execution and placement. There is a broad range of views exploring why people notice it; some based on medium and integration (Dahlén, 2005;Jurca and Madlberger, 2015), some on the specific elements and scale that attract attention (Hutter, 2015;Yuen, 2017) some on how people engage through experience (Gambetti, 2010), some on whether it surprises (Hutter and Hoffmann, 2014), with little on placement.
There is growing consensus that ambient advertising does not need to be positioned near a point of sale or generate a call to action (Gambetti, 2010;Saucet and Cova, 2015), though there is little research into this. While there is a small body of research that acknowledges that ambient advertising can be a low-cost tool (Gambetti, 2010;Hutter and Hoffman, 2011;Turk, Newing and Newton 2006), none have checked if people engage with it. Most researchers agree that ambient advertising can share a message with an audience by asking them to decode it, but none have developed fieldwork to test this. While it is clear there is a good body of research into engagement there are gaps which can be researched.

Methodology
The study compares work on engagement by academics with the industry knowledge of advertising creatives. This is then triangulated with fieldwork using two media interventions with participants to examine audience engagement on location. A mixed methods approach was deemed appropriate for conducting this study. I will show why audiences engage with ambient advertising; if they are prepared to engage with ambient advertising far from a point of sale; if they will engage with a low-cost form of ambient advertising and if the ambient advert causes them to think about the message.
Mixed methods as a methodological framework is accepted across a number of disciplines as valid and verifiable approach to research (Alise and Teddlie, 2010;Ivankova and Wingo, 2018). It is most commonly used to allow researchers to integrate both qualitative and quantitative findings (Tashakkori and Creswell, 2007). Additionally, it is an established approach to probe 'both exploratory and confirmatory questions within a single study' (Ivankova and Wingo, 2018, 980).
This research project seeks to compare findings from the literature with current industry thinking, and findings from applied in-field research with participants. This is both an exploratory and confirmatory endeavour designed to reveal engagement with ambient advertising in the round (Teddlie and Tashakkori, 2009). As a framework it allows for diversity of thought and accommodates real-life experiences and ' contextual understandings' (Ivankova and Wingo, 2018, 980). Mixed methods is an approach that allows for both multiple methods in the data collection phase and analysis phase of a research design (Tashakkori and Creswell, 2007). The aim of this research is to compare engagement with ambient advertising from three different spheres of knowledge and contextual understandings.
The information gathering phase of this research uses in-depth semi-structured interviews with industry practitioners, and visual, sensory and live ethnographic methods (Pink, 2008) with participants as fieldwork. The analysis phase uses content analysis to make 'replicable and valid' assertions (Krippendorff and Bock, 2009). It then applies triangulation as a method to draw quantitative and qualitative data together, not to simply cross-validate, but to explore the phenomenon of ambient adverts from different perspectives (Berg and Berg, 1993;Denzin, 1978).

Ethical approval
Ethical approval for interviewing the advertising creatives (see Table 1) was straightforward. They were all contacted in advance and the scope of the research -as both part of a larger PhD study and for use in individual papers -was made clear. The creatives were all offered the opportunity to read their transcripts and remove anything that they did not wish to be included. They were offered the opportunity to remain anonymous, but all declined.
Ethical approval for the participant journeys was a more involved process. The participants could not be told in advance about the research focus as that would defeat the purpose of research on engagement. Obtaining consent became part of a three-stage informed consent process. Their first consent form asked them to be observant of their environment, without being directive in their briefing and in forms (Kvale, 1996) and was given before the walk. The second form, given straight after the field interview, clearly stated that the interest was the ambient advert in the context of their walk. The final consent form gave them sufficient time to look over their own recordings and ask for them to be removed. Zlatan Krajina (2014) used a similar approach in his study. I made it clear from the start that my research required the use of data gathering devices such as audio recorders and digital cameras and that participant's anonymity might be compromised if they were to photograph themselves. The participants understood that the research was part of a larger PhD study and associated papers from the outset.

Interviews
The interviews with advertising creatives were also part of a PhD study investigating ambient advertising more broadly. The selection of questions and answers presented here centre around the topic of audience engagement, though the creatives' wider perspectives on current use of ambient advertising have informed the context of this paper.
In relation to the aims of this paper they were asked; • Why do audiences engage with ambient advertising?
• Does ambient advertising need to be near a point of sale?
• Do scale and production values increase engagement?
• Would audiences engage with a low-cost form of ambient advertising?
• Does ambient advertising entice audiences to think about the message?
Similar to Biraghi et al (2015), semi-structured interviews were conducted. The interviews lasted about one and a half hours at a range of locations, either at participant offices or at local coffee shops. Unlike Biraghi et al's study, the focus was on creatives rather than account people or strategists. There were fifteen participants in total, nine were male, six were female. They came from a variety of agencies from advertising to branding to activism. Two creative teams were interviewed, and they have been counted as separate people as they offer different points of view.

Findings
What emerged from the discussion is that ten of the fifteen believed that a passer-by would notice an ambient advert if they came past it, If it intrigues them then actually, they might go and investigate it, you wouldn't get anyone investigating a normal ad. (Nelson and Sutherland,interview,22 February The five that were unsure mostly worked in design or experiential agencies. Those five also felt it to be a risky medium. It's a risk -because you're just putting it out there and hoping for the best. (Edwards, interview, 30 December 2019) This meant that 81% of those from the advertising agencies were convinced people would see it. Nine put this down to a combination of placement and idea working together. They described the importance of placement and medium as a way to provide both physical and cognitive context to ambient advertising, with ten of the fifteen believing that both were equally important, stressing that they are integral to the creative idea.
[It is] where medium and message become inseparable, and because they are symbiotic the power is dialled up massively to a point where you cannot ignore it. (Tindall,interview,10 October 2019) They also veered heavily on the side of placement in this discussion with seven of the nine mentioning placement first: Calm [project84] only got the attention it did because it was on top of the ITV building. (Tollet, interview, 1 November 2019) Two interviewees believed that people notice ambient advertising if it feels relevant to them in some way -to their own activities and interests, and just two believed that people notice it because it is some sort of disruption to the norm. Just over half, eight interviewees, believed that people would engage further to try and decode the advert. A further three added that only if it seemed relevant to the audience in context would they engage further than simply noticing it. Interestingly, they all believed that a modicum of surprise was necessary in order to affect passers-by, to surprise them out of their day-to-day behaviours and practices.
It something that makes you step out of your everyday routine and surprises youjust for long enough to take note that you've not seen before. (Denney,interview,14 November 2019) When asked if ambient advertising should be near a point of sale thirteen of them said 'no', the two that said 'yes 'worked in experiential/design agencies which indicated that they were looking at it through their own working lens.
I can't think of many [ambient adverts] that are [a point-of-sale] -or at least they might not have been very good because they were trying too hard. (Daltry, interview, 5 July 2019) Scale and production values as factors that lead to increased engagement was more divisive. Ten believed it did not increase audience engagement: The satisfaction in ambient is that it's discoverable, if it is too big and too out of context then it is no longer ambient. And you can often be a bit cheekier and more nimble with a smaller budget. (Grimer, Interview, 18 November 2019) Well, it attracts the media more, but on an individual level it wouldn't make someone more likely to interact with an ambient ad. (Neighbour, interview, 18 December 2019) However, five did believe it increased engagement from a range of advertising and experiential agencies, but for a range of reasons. Looking at those that responded in the affirmative, they had recently made large scale works so could have been considering the matter reflecting a specific view on the work they have just completed. The rest touched on having some sort of a budget to execute the idea well and to stop it feeling like flyposting, or some other illegal activity. They also spoke about the extra pressures for measuring effectiveness that come with budget.
It makes it easier to do work when there is a decent budget, but with budget comes greater expectation. But no, I don't think people engage any more than they would have done just because something is bigger. It's perhaps the opposite. (Oudot and Leach,interview,5 July 2019 [Oudot]) This led onto the next area for discussion, does ambient advertising have the ability to make people think? Thirteen said 'yes', that audiences would try to decode what they had found. The two that didn't know came from design agencies. This idea of decoding or working out the meaning had also been picked up by some interviewees earlier when asked why people engage. In all, at some point during the interviews, they all mentioned decoding as part of engagement.

Conclusion
All the interviewees mentioned that audiences would try and work out the meaning. This means that everyone from this small industry sample believes that decoding is integral to ambient advertising, it is part of the engagement process, and that all of those engaged would do it. Audiences have developed a certain amount of advertising literacy (O'Donahoe and Tynan, 1998), and have learnt to decode advertising that is framed more traditionally, such as in a poster or TV advert. In many ways, the code is presented alongside the way to crack the code: the advertising frame. In these frames audiences easily make connections between seemingly disparate elements (Pracejus, Olsen and O'Guinn 2006). In ambient advertising this is not so obvious. The audience doesn't know why the various elements have been placed in a particular site. The unexpectedness of the elements and their relationship to the environment and to each other is intriguing and invites decoding. When the world is re-presented in such playful ways there is a small cognitive pleasure in cracking the code and piecing together the meaning. They also put placement, and the fit between placement, idea and medium, as the main drivers for engagement, with the majority adding roundly that it should not be treated as point-of-sale. This indicates that, for advertising creatives, effectiveness is measured by engagement and decoding rather than a direct purchase. This considerably opens up the places that ambient advertising could be tested in. While 66% didn't think scale and production values changed engagement, scale and dimensions of particular elements have been a focus of a fair amount of academic interest (Hutter, 2015;Yuen, 2017). A number of interviewees added that a certain amount of production value stops something looking cheap, something that would reflect poorly on the brand. This has implications for the guerrilla end of ambient where stickering is common.

Field experiments
There were four field experiments. Forty participants responded to the call out in four groups of ten, all together 39 were able to participate on the given dates.
The experiment and methods used were designed to investigate; • If the participants engaged with the ambient advert • Why they engaged • If it needed to be near a point of sale to make sense • Do scale and production values increase engagement?
• Are viewers prepared to engage with a low-cost form of ambient advertising? • Do they take time to think about the message?
The methods used were • A lab • Video and walking diary -through a lapel camera which both records an audio walkingdiary and captures context (Pauwels, 2012;Pink, 2007) • Autophotography -to record participant interest or things that they found significant (Glaw et al., 2017) • Field interviews -to ascertain whether they had commented on and photographed everything that they had considered to be important (Berg, 2009;Krajina, 2014).
All the field experiments have taken place in an alleyway. It is a controlled environment that functions as a lab. Abdul-Razzaq, Ozanne and Fortin (2009) found that participants were more likely to notice ambient advertising in enclosed environments. All the participants walked past the ambient advert, allowing the experiment to focus on engagement rather than whether the participants walked past it at all. Both the literature and the interviews indicated that the ambient advert did not need to be near a point of sale.
In the experiment, I designed an ambient advert to send a message on behalf of the local council based on Hutter's findings (2015) that only one in five ambient adverts sells consumer goods. In common with much ambient advertising, I adapted existing street furniture -in this instance a lamppost. The advert for experiments 1-3 was a large pink bow and an oversized gift-tag with the copy 'Thank you. This lamppost was paid for by your tax contribution.' (See Figure 1). Experiment 4 had a large silver bow and an excessively large silver-backed gift tag which read 'Thank you for your tax contribution which paid for all the lampposts that light up your streets.' The lamppost itself was also partially wrapped with branded wrapping paper for experiment 4 (see Figure 2).
The public sample group was initially recruited from a local school's 'mum's Whatsapp group.' The advantages of this purposive sampling technique (Etikan et al., 2016) would be to find ' existential insiders' (Relph, 1976, 53) to whom the alleyway had some meaning that would notice something that stood out from the ordinary. These individuals would also be more inclined to make time for the project because of proximity. Following this, each participant recruited a man that would be willing to take part in the research. A snowballing recruitment technique followed for the subsequent three experiments, generating a roughly equal male/female ratio and ages ranging from 18-53. There are clear limitations using this method of sampling. The individuals are from broadly the same socio-economic group and people with ages from age late 30s upwards were more likely to participate. This might mean that they would respond in a broadly similar way.

Findings
The walking diaries collected information on everything the participants noticed. A total of 97% of the 39 participants walking through the alleyway noticed the advert. In addition, 85% of the participants took photos of it. This was the most common thing to be photographed. All the participants that noticed it commented that it was new to the alleyway. They had not seen it before, and this intrigued them sufficiently to go and have a look at what it was. Roughly half noticed the colour and the other half noticed it was a ribbon or present from a distance.
'What is this pink thing on the lamppost?' She stops to take a photograph. Participant V1 No-one asked what the ambient advert was doing in the alleyway, and no-one commented that the advert would be better near the council offices -similar to point-of sale. In the field interviews that followed, a number of the participants wondered if there would be messages on some of the other lampposts, and why that lamppost in particular was important. Some even felt that the lamppost was new -this is despite the fact that they walk down the alleyway regularly -on average one participant per group. This indicates that until their attention had been drawn to the lamppost it was almost invisible. Few of the men talked about the light that the lamppost gave at night, roughly one from each group. This was much more relevant to the women with all the women mentioning it from each group. While the extra lighting was relevant to the women, it didn't improve their perception of the council.
A pretty dramatic difference was the number of participants talking about other distractions within the physical context of the alleyway across the four experiments. All the experiments were placed on the same lamppost. In experiments 1-3, participants were consistently distracted by a variety of other features of the alleyway. However, participants were intrigued by the larger ambient ad with higher production values in experiment 4 some time before they got to it. They were also more likely to touch it with a number holding the gift tag and flipping it round.
So, from a distance I can see something that's wrapped up on a lamppost that is really intriguing, so suddenly nothing else round here is as interesting, obviously… He walks up to the ad 'Bromley Council,' He takes a photo 'that's very nice.' Participant M4a Once they had engaged, they all understood what it was. Across all four experiments, 59% read out the advertising copy with a further 69% commenting on it further. They spent on average of between 23-28 seconds thinking about the advert, including walking up to it, reading it and continuing to comment on it after leaving. This means the advert wasn't just seen, it was engaged with.
She pauses in front of the ambient ad. 'Ah, that's cute' she said in an upbeat tone 'I'm not sure I'm not supposed to take a lamppost for granted, that's a funny thing to be celebrating,'; she walks away adding, in a pessimistic tone, 'that makes me feel there's going to be more cuts.' Participant C1 The field interviews showed that not only had they decoded the meaning, but that in experiments 1-3 five to six participants from each group remembered the brand. However, this rose sharply in experiment 4 with all ten recalling the brand. This group also contained an 18-year-old that commented: I didn't know Bromley could be thought of as a 'thing' until I saw it on the ad. Participant W4 Experiment 4 had the advert with slightly higher production value and advertising craft applied and was slightly larger in scale.
The engagement with the ambient adverts was very high, with a high proportion of participants seeing it and interacting with it. Once they had interacted with it, they continued to think about it. This was evident within each experiment as well as in the experiments as a whole; the numbers did not vary wildly. Acknowledging that the numbers of participants thus far are small -39 participants (1 from the 40 was unable to attend on the given date) -there is some robustness to the consistency of responses. While some small boost in scale and production value increased focus, it didn't make participants like the message or brand any more than in experiments 1-3. The higher production value seemed to increase interactivity -perhaps because it felt slightly less 'grubby' to borrow a phrase from the advertising creatives. The higher production value also seemed to improve brand recall. The placement of this advert was key, since there were a number of distractions where the audience would go, part of their everyday environment.

Discussion
I have reported findings from the literature, interviews with advertising creatives and created two media interventions designed to ascertain participant engagement with ambient advertising. There were four key research objectives: • Why do audiences engage with ambient advertising? • Does an ambient advert need to be near a point of sale? • Will audiences engage with a low-cost form of advertising? • Do audiences of ambient advertising think about the message?
The engagement with the ambient adverts was very high, much higher than either academic studies or advertising creatives had considered that it would be. It is clear that people are prepared to engage with ambient advertising and this links to objective two, particularly if it is placed in the right location. Objective two appears to be answered by acknowledging that ambient advertising does not need to be near a point of sale. Sixty nine percent of participants engaged further: they considered the lighting, or their opinion on the council, to be directly relevant to them. This supports the insight from advertising creatives where over half thought public participants would do so if it was relevant to them in some way. Even though the advert was nowhere near a point of sale, it had remarkably high brand recall. One possibility is that it stood out precisely because it was far away from all other advertising forms and was unexpected.
All the industry interviews indicated that they thought ambient advertising needed to surprise, just enough to jolt someone out of their day-to-day practices; this was why people engaged. This was supported by the reactions of the passers-by in the field experiments that all had some small surprise in seeing this unusual object in the alley. One hundred percent of the participants that noticed the ambient advert also noticed that it was out of the ordinary and a new 'thing,' half the time commenting additionally on colour or material. The newness of the object would appear to override other considerations such as whether the viewed object is 3D or an optical illusion, a focus of much academic categorisation.
The third objective dealt with cost. All the participants that noticed the advert did not hesitate to engage with a low-cost form of advertising. That said it wasn't as low-cost as stickering and didn't enter the 'grubbier' end of ambient. However, when the production value went up in experiment 4, they interacted more and focused earlier. This bears out the creatives' opinions, that increased spend can help realise the idea better, which might lead to more engagement, but that much bigger budgets are more about engaging mainstream media.
The fourth objective investigated whether audiences thought about the message in an ambient advert. Eighty six percent of the creatives interviewed thought that they would try to decode the message, and this was supported by Borghini et al's (2010) study of street art and ambient campaigns. Indeed, that is what the participants did, with 69% commenting on the advert further, placing it into the context of their own lives and opinions. Experiments 1-3 had six participants from each group recalling the brand and experiment 4 showed all participants recalling the brand. They all understood what was being said and by whom; they simply didn't all agree with it showing quite a deep level of processing and engagement with the underlying message.
This research had limitations. It used a small sample group for both the interviews and the fieldwork. There was a very limited number of questions asked about engagement. Furthermore, ambient advertising is usually deployed as a support to a larger campaign. As an industry practitioner I would have seen the merits in having other media supporting this idea and a number of different ambient executions; the situation was not exactly as one might find it in a real campaign. This, in turn, may have limited the persuasive power of a single advert to change opinion of a brand.

Conclusion
The reason for doing this research is to question whether audiences are prepared to engage with low-cost ambient advertising away from point-of-sale. If they are, it can be a useful, tactical and immediate response for smaller organisations and social activists seeking to do good with small budgets. Hutter (2015) noted that there is little research that proves empirically that passers-by would engage with ambient advertising. Advertising creatives believed audiences would engage and this limited study indicates that they do.
The two executions in the experiments were low-cost and were noticed by almost all participants. The engagement with the ambient adverts was very high, much higher than either academic studies or advertising creatives had considered. This has implications for considering the use of ambient advertising across a number of sectors. There hasn't been much of this smaller low-cost ambient advertising created by big agencies recently as creatives and clients have moved towards spectacles and special builds to engage media attention. This means that it is being missed as a messaging opportunity. This smaller, cheaper means of advertising can clearly communicate brand and message far away from usual advertising environments.
Taken away from the simplicity of the cause and effect of point-of-sale advertising, ambient advertising has the ability to affect people in their everyday spaces, making messages more relevant to location and communities. Hubbub's 'What's in my Wash' changed the attitudes of shoppers to microfibres while they were engaged in the activity of shopping in Bond Street. The Columbia Road Cartel's ambient campaign, highlighting the easy procurement of drugs, changed the attitude of both the police and the local council.
This ability to get people to think about the message in the context of their own lives is what makes ambient advertising so compelling. It can provide a useful and affordable tool for advertising for social good and social change.

Biographical Statement
Miriam Sorrentino is a Senior Lecturer in Visual Communications at the University of Greenwich. She is a Fellow of the Higher Education Academy and a D&AD and ISTD awarded lecturer. She is currently a PhD candidate at UAL. Miriam brings over 20 years' experience in advertising and design at some of London's most awarded agencies with work for Leo Burnett's, Mother and Grey Interactive for a wide variety of clients as well as a body of work for the BBC and Channel 4 to her teaching and consultancy work. Laurence King commissioned Miriam to write the academic text Creative Advertising: An Introduction, published in 2014, an overview of current advertising practice and theory. In 2019 she co-edited and designed Publishing and Digital Culture: Agility, Community, Collaboration published by the Stephen Lawrence Gallery.