Introduction

Smartphones currently are one of the main ways people access the Internet, and mobile traffic has surpassed desktop access in Western societies. Given that advertising needs to reach its target public, logically its aim is to be visible to its audience’s screens and, ideally, be seen and recognized. Equally evident is the challenge of getting user’s attention given the wide variety of smartphone uses and the personal nature of their use. These features increase smartphone users’ sensitivity toward the type of messages they receive (^{Park et al., 2008}).

The significance of the smartphone as a means of reaching an increasingly diverse audience has been followed by an interest in analyzing the attitude of users towards the messages received on these devices (^{Leppaniemi & Karjaluoto, 2005}), the effectiveness of certain messages or mobile technologies (^{Leek & Christodoulides, 2009}), the variety of user attitudes and responses to commercial and non-commercial content (^{Altobello & Bruner, 2008}), and differences attributable to user profiles (^{Ünal et al., 2011}).

As mobile phones become a multipurpose, personal and more ubiquitous object, advertising adapts to the consolidation of apps (^{Marchetti, 2016}; ^{Martins & Enes, 2020}) and to optimizing for screen sizes.

Mobile advertising and young users

Mobile devices, smartphones or tablets are the fastest growing digital advertising medium (^{Taken, 2019}). Two approaches can be taken to understand mobile advertising: one considers mobile phones as just another medium that reproduces conventional formats and models; the other endows mobiles with technological specificity (location, interactivity, social connectivity, etc.) and thus considers smartphones as suitable for exploring innovative formats (^{Martínez Martínez & Aguado, 2014}). Advertising formats range widely, such as messaging, emailing, etc. In terms of content, variety can include apps (advergaming, appvertising) or access to branded content. Not surprisingly, as stated by ^{Wielki (2020)}, product, services or brand promotion has increased in complexity and difficulty.

The dynamism of the device itself is an additional factor which mobile advertising must consider. According to ^{Atkinson (2013)}, this process includes adapting to how messages are delivered in as much as how consumers become part of the mobile communication process, by developing increasingly digital, participatory and less intrusive content. This scenario marks the origin of the popularity of hybrid content (Kim et al., 2016) particularly influencer marketing which has become a topic in which various authors have raised their concerns on the blurring limits between content and advertising (^{An & Kang, 2014}; ^{Chen et al., 2013}; ^{Terlutter & Capella 2013}). This issue becomes particularly significant when vulnerable audiences are involved (^{Van Reijmersdal & Rozendaal, 2020}).

^{Liu-Thompkins (2019)} in her review of the scientific literature on digital advertising points out the relevance of the works that have analyzed the mechanisms by which online advertising accompanies consumers, a process that begins by capturing and maintaining their attention and lasts until consumer engagement is achieved. Customer attention at the moment of exposure to an ad can be key to achieving his or her action (^{Calder et al., 2009}; ^{Teixeira et al., 2012}), and elements such as format, brand or location of the ad may be involved.

Many elements may play into achieving consumer attention or positive receptivity. According to ^{Park et al. (2008)}, the effectiveness of mobile advertising is influenced by factors related to the advertisement itself, the target audience and context or environment in which the ad is received. ^{Grewal et al. (2016)} states that factors defining the user’s context (physical location, time of day, weather conditions) and the consumer him/herself (phase of his/her customer journey, personal customer history) are particularly relevant and should be considered and analyzed in more detail. ^{Grewal et al. (2016)} establishes a gradation within the response itself and enumerates the stages as: 1) awareness/ attention; 2) engagement; 3) purchase interest; 4) conversion; 5) repurchase or advocacy. How consumers progress from one stage to the next, or the possible effects on how consumers interact with advertising is the aforementioned customer accompaniment to which ^{Liu-Thompkins (2019)} grants special relevance.

Along these lines, this study relates the extent of interaction with digital advertising and three elements of advertisement: the format (^{Llorente-Barroso, 2013}; ^{Rebollo-Bueno, 2019}; ^{Romero & Fanjul, 2010}), the platform on which it is located (^{Greenberg, 2012}; ^{Jessen & Rodway, 2010}; ^{Simola et al., 2011}) and the type of product advertised (^{ditrendia, 2021}; ^{IAB Spain, 2021}). The relevance of these variables in the web context has been well established. The aim is to check whether the same proves to be true in the mobile context.

Indeed, in the web environment, user response to advertising formats varies. For example, display advertising generates much lower response rates than that generated by native advertising (^{Maestro-Espínola et al., 2019}); advertising on social networks (^{Núñez-Gómez et al., 2020}; ^{Pintado & Sánchez, 2018}); the advergaming (^{An & Kang, 2014}; ^{Mallinckrodt & Mizerski, 2007}; ^{Van Reijmersdal et al., 2012}; ^{Vanwesenbeeck et al., 2017}) or influencer marketing (^{Feijoo & Sádaba, 2021a}; ^{Lou et al., 2019}; ^{Lou & Yuan, 2019}; ^{Trivedi & Sama, 2020}; ^{Zozaya & Sádaba, 2022}). This study analyzes formats on mobile devices and aims to see whether within the mobile scenario the role of advertising format is as significant as it is in the web scenario.

Likewise, Internet advertising works differently depending on the context in which ads are placed; consequently ad location is as decisive a factor when aiming to attract web users (^{Greenberg, 2012}) as it is to attracting mobile users (^{Feijoo & Sádaba, 2021b}). Predictability in ad placement increases user’s ability to ignore ads (^{Jessen & Rodway, 2010}). Thus attractive placements, such as insertion in video games, are chosen aiming at transferring the positive feelings generated by the context to the advertisement and the brand itself (^{Mallinckrodt & Mizerski, 2007}; ^{Van Reijmersdal et al., 2012}; ^{Vanwesenbeeck et al., 2017}).

Personalization is a particularly valued feature in digital and social advertising (^{ditrendia, 2021}; ^{IAB Spain, 2021}; ^{Pintado & Sánchez, 2018}), hence the type of advertised product is also considered key in attracting user’s attention.

User’s clicking on ads is one of the ways in which user interaction with digital advertising is measured (^{Greenberg, 2012}). Several studies on web interaction have shown that mouse pointer gestures (movements, clicks, etc.) and eye movements are correlated and, by extension, with attention and intentionality (^{Huang et al., 2011}). In this line, this study assigns the highest level of interaction to clicking. Also considered is gaze dwell time (that is, gaze fixation), another indicator of attention (^{Chen et al., 2001}).

Thus, the following RQ is proposed: Is there an association between the level of interaction generated by an ad on a cell phone and (a) its format; (b) the platform on which it is located; and (c) the type of product that is promoted?

Nowadays the younger generations, children, and teenagers, are also using smartphones intensively to communicate and for entertainment, and thus have become part of the online audience as well as occasional active consumers (^{Stirratt, 2016}; ^{Taken, 2019}). It is pertinent to question whether their vision of and attitude toward advertising is different from that of adults (^{Kirk et al., 2015}). The review by ^{Liu-Thompkis (2019)} revealed the limitations of research on this audience, bringing to light once again children’s vulnerabilities to the growing phenomenon of online advertising (e.g., ^{Rifon et al., 2014}; ^{Van Reijmersdal, et al., 2012}).

Methodology

This exploratory research seeks to shed light on the level of interaction that mobile advertising triggers among the new generations of smartphone users, particularly minors ages 10 to 14. Three key elements of mobile advertising (advertising format, advertiser category and the platform on which it is located) could be influential in determining the level of interaction. Ultimately, this research aims to provide in-context evidence on the attention that smartphone advertising mobilizes in users.

The selected data collection methodology is one of the contributions made by this research. Minors’ daily routine on their smartphone was recorded on the device they used most, and thus the data collected stem from the users’ browsing history itself compared to other data collection methods in which participants are provided with phones for research purposes.

Digital ethnography was used to ensure the information obtained was as close as possible to the reality being studied, in this case, the recording of advertising consumption on the mobile phone most used by minors. The need to collect data as naturalistically and discreetly as possible (Hine, 2000), and thus analyze their spontaneous routine with the device drove this choice. Researchers studying digital inclusion and the appropriation of the Internet in a “natural” environment (^{Bakardjieva, 2005}; ^{Leung, 2005}) have widely used this technique.

This study was based on a non-participant digital observation by the research team. Minors themselves recorded the screen of their device (screen recorder) and recordings of movements and contents visited while using the mobile device were obtained.

The nature of this project leads to reflect on the application of ethnographic methods and ethical considerations regarding the participation of minors in field work. To safeguard the integrity of participants and researchers, prior to data collection an informed written consent authorization was requested from the minor’s legal guardian and by the minor him/herself. This informed written consent had been previously reviewed and validated by the Ethics Committee of the university to which the research project is attached (University of Los Andes).

Finally, the participant or legal guardian sent the audiovisual pieces to those responsible for the investigation through WhatsApp or email. A minimum duration was requested to guarantee the quality of the observation, specifically, each recording sent was to last no less than five minutes in which routine use and advertising exposure were recorded. Recordings were performed throughout one week (from Monday to Sunday), ideally generating material per day. The instructions provided to the responsible adult recommended that data should be collected during routine use, so the data collected would be close to the reality of the user. The non-participant nature of the method, and thus the fact the recordings were made without the supervision of the researcher, led to some unforeseen events and imbalances in the information collection process, such as irregularities in the number of videos sent and in their duration. This field work was conducted between May and September 2019.

A total of 45 users (parental mobile N = 17, own mobile N = 28; male N = 14, female N= 31; ages 10-12 years N = 21, ages 13-14 N = 24) underwent monitoring. The longitudinal nature of the study, and the invasiveness of the method, made it difficult to confirm the participation of the sample. Finally, 356 recordings were collected, which registered a total of 41 hours, 45 minutes and 39 seconds of recording and a total count of 2 410 advertisements.

Digital ethnography methodology was followed to collect the information. However, the audiovisual record obtained was subject to content analysis and thus the type of advertisements that minors receive on their mobile phone and with which they interact the most could be analyzed using the statistical program SPSS. Content analysis for this study was performed on a matrix comprising the following variables:

Results

Discussion

Mobile phones have become a personal and omnipresent object and present the advertising world with advantages that are not accessible to other media and platforms.

As a consequence, in addition to increasing sense of intimacy during individual consumption, the interaction between phone user and advertising message can be enhanced and lengthened.

Display ads were the type most present in the sample studied (50%). This is the most conventional and recurrent format in digital advertising and is characterized by low click rates. This would verify that smartphones are mostly used to reproduce multiplatform formats. Only a minority advertising would have been thought of ad hoc and would seek a less direct, simpler, and more empathetic way to connect (^{Martínez Martínez & Aguado, 2014}).

Thus, no interaction was recorded for 76.6% of the ads analyzed, a percentage that increases to 92% in the case of advertising in display format. Display formats on mobile contexts also present low clicking rates, 5.5% of the cases studied. On the contrary, attention and clicks on commercial content published by influencers in their corresponding social networks was significant, which corroborates the predisposition and interest that this type of publications arouses among the new generations also through the mobile phone (^{Van-Dam & Van Reijmersdal, 2019}).

Regarding platforms and channels, it seems that ads placed on social networks attract the attention of the user, both visually and by clicking. However, these advertising messages must provide added value considered as interesting and attractive to their audience: raffles, promotions, discounts, or entertainment (^{De-Cicco et al., 2020}; ^{Kantar, 2017}). Clicking interaction in an apparently favorable context such as video games is low.

Another relevant issue is the direct relationship observed between advertising brand category and click interaction. The click interaction was higher in the case of ads for toys, electronics, culture and education and entertainment, topics related to minors’ consumer interests (10-14 years). It is noteworthy pointing at the great variety of differentiated brand categories, with products and services in the field of health, real estate, finance, and home / decoration / cleaning that could be considered far from the interests of minors. These finding highlights one of the limitations of behavioral advertising, which segments advertising based on browsing history, a register that is based on the information collected while a device is being used, in this case, by different users with very different consumption profiles, parents and children, for instance. This results can open new lines of research thanks to the methodology used that made it possible to record the actual use on the device itself.

Thus, it is curious to see that this study did record the use of registered apps as an advertising medium, but not as marketing tools (brand apps). About 85% of the ads were viewed through apps, but preferably to host display advertising.

Interpreting clicking as interaction does pose some limitations (^{Greenberg, 2012}): as clicking may be the only alternative users have to avoid advertising and continue with the activity in which users were engaged. Having to repeatedly click on ads in order to continue browsing irritates users (^{Kantar, 2017}; ^{Martí-Parreño et al., 2013}; ^{Martí-Pellón & Saunders, 2015}). Future qualitative research should aim to assess the clicking “quality” registered by the ads.

Conclusions

This paper reveals the increasing pressure exerted by advertisers on mobile phone users by accessing real browsing routines: for every minute in front of a smartphone, screen users are exposed to almost one complete ad. Thus, there is a need to learn how to increase message effectiveness (^{Grewal et al., 2016}), analyzed how context influences user reactions and register how phone users react to advertising. Based on the results analyzed, mobile phones have become a screen with which users achieve greater interaction when they can opt for pull advertising that offers added value such as fun or entertainment.

Lastly, the intensive presence of advertising on minors’ devices which includes content clearly aimed at an adult audience (^{Boerman, 2017}) must keep us alert. Minors are considered a vulnerable audience and the adult world should ponder the need to be vigilant regarding children’s exposure to advertising (^{Van Reijmersdal et al., 2012}).