A quick test: how many of you can name the product being advertised in the banner ad at the top of the page? Chances are, the ad's presence didn't even register with most seasoned web browsers. But that's probably okay, at least according to research that appears in June's Journal of Consumer Research. The research concludes that repeated exposure to a product via banner ads generates a positive feeling towards that product. The good news for consumers is that a critical reevaluation of the product can make these positive feelings vanish.

There is a long history of experiments that show that repeated exposure to a stimulus that's barely perceptible can enhance a person's feelings towards what's otherwise a neutral object. These feelings can include a liking or more subjective things such as "fame, truth, duration, loudness, stimulus brightness and darkness." The authors hypothesized that banner ads should work well as such a stimulus, given that "most viewers pay minimal attention to banner ads."

To test this, they asked students to read a multipage essay under the assumption that they'd be answering questions on the essay's content. Instead, the students were ultimately quizzed about a fictitious brand of camera, Pretec, that had appeared in banner ads on the pages that contained the essay. Different pools of students were exposed to Pretec ads zero, five, or 20 times.

Afterwards, when asked about their negative feelings towards the brand, the number of exposures made absolutely no difference. In contrast, those students asked about their positive feelings towards the brand saw those feelings increase in a linear fashion based on the number of exposures. In fact, the authors noted that the positive vibes still appeared to be going up after 20 exposures, leading them to wonder where this effect might start leveling off.

There are apparently two models competing to explain this phenomenon. The first proposes that people will more readily assign positive properties to something that they can remember more readily. The second suggests that the processing of even minimal exposures can create an actual positive evaluation (for example, the conclusion that the item is not a threat). That positive affect then influences future evaluations.

To determine which of these may be at play, the authors took another pool of students and asked them to make a similar evaluation but attempt to do so without considering the familiarity of Pretec. In that case, the positive effect vanished, suggesting that the first model was correct. To nail this point down, the authors played music during the time the students viewed the banner ads. When asking their feelings, they warned the students (falsely) that the music might create a positive impression of Pretec. This false warning also eliminated the positive effect, suggesting that it was simply based on familiarity and not backed up by any real positive evaluation.

So, the psychologists have a better grip on their theories, and advertisers have a few things to consider. The first is that banner ads may provide a valuable function in fostering familiarity even if those that view them never click through to the source of the ads. The downside for advertisers is that any evaluation of the positive impressions that this familiarity creates, even one based on false premises, is enough to make those positive feelings vanish. This suggests that familiarity-based advertising may work best for impulse buys, where more detailed evaluations aren't likely to occur. More importantly, this gives us a glimpse into the way our unconscious works with visual stimuli.