What’s the difference between a search service and a service perfectly targeting informative advertising to its users? Susan Wojcicki, Google VP, Product Management, recently stated:
Google’s advertising business was founded on the core principle that advertising should deliver the right information to the right person at the right time. This is very similar to our mission in search, and, like our colleagues in search, those of us on the ads team are constantly striving to achieve better results.
Daniel Tunkelang insightfully responded:
Google insists that it maintains a wall between its search and advertising businesses. But Wojcicki’s post–which is on Google’s official blog–suggests otherwise, at least in spirit. If Google believes that both search and advertising aim to “offer relevant content” and “deliver the right information to the right person at the right time”, then why put up a wall at all?
If an advertising platform truly provides only the most relevant, useful, timely information to its users, it gives advertisers no incentive to bid against each other to place ads. The most relevant, useful, timely ad, not the highest bidding advertiser, would be presented to users. Ad results wouldn’t differ from search results. The perfect advertising service would provide no incentive for advertising expenses.
For both search and advertising, emphasizing relevant, useful, timely information obscures the importance of emotions in human decision-making. A vast amount of information is subconsciously processed within the human body. Only some of this information is brought into the brain’s working memory and higher-order cortical regions. Competing for attention is not just the business of advertising. Emotions have a major role in the ongoing competition for attention within the human brain.
Actually making a decision requires a motivational push, not just information processing. In an influential book describing new understanding of emotions, a neuroscientist described the behavior of a patient with damage to brain regions associated with emotional processing. The patient was offered the choice between two dates for a laboratory appointment:
For the better part of a half-hour, the patient enumerated reasons for and against each of the two dates: previous engagements, proximity to other engagements, possible meteorological conditions, virtually anything that one could reasonably think about concerning a simple date. Just as calmly as he had driven over the ice, and recounted that episode, he was now walking us through a tiresome cost-benefit analysis, an endless outlining and fruitless comparison of options and possible consequences.
When the doctors finally halted this process and asked the patient to come on the second of the two dates, the patient was happy to accept that choice. Human-Computer Information Retrieval services should not be implicitly modeled on the behavior of emotionally damaged humans and emotionless computers. An impulse to choose, apart from organizing and accessing information, is a key aspect of human search behavior that concludes with choice.
Search and advertising involve much different emotional patterns in users’ information processing. Web search produces a list of choices designed to be informative, not emotive. Given the importance of search result rankings to users’ choices, users seem to view these results with a feeling “tell me right now” and “whatever, good enough.” The emotional drive is not primarily to make a good choice, but to go somewhere, to finish the search.
Advertising has much more specific emotional targeting than search. Advertisers design brand names and tag lines to be emotive. Where possible, they use images and audio-visual materials that evoke favorable feelings. Compared to clicking on search results, users are much more likely to click on an advertisement based on emotions that the specific advertisement generates.
Because emotions are an integral aspect of human information-processing and decision-making, advertising’s future is secure. Even if they perfectly target ads to be relevant, useful, and timely for users, advertising platforms cannot effectively rank the emotional value of ads. Persons and companies have deep-seated feelings about how good they and their products are. These feelings are fully sufficient to drive vigorous bidding for advertising opportunities.
Search will not replace advertising. Information technology can greatly improve human’s ability to organize, rank, and make accessible information. No such technology exists for human emotions. That fact will keep advertising platforms in business.
 Damasio, Antonio R. (1994) Descartes’ error: emotion, reason, and the human brain (New York: Putnam) pp. 193-4. Skin conductance responses, which typically are correlated with emotional responses, have been documented to precede a risky choice in normal individuals. Such a response does not occur for individuals with bilateral damage to the ventromedial prefrontal cortices. The later persons’ choices systematically differ from normal persons’ choices within the same laboratory experiment. See Bechara, Antoine, Hanna Damasio, Daniel Tranel, and Antonio R. Damasio, “Deciding Advantageously Before Knowing the Advantageous Strategy,” Science, V. 275, 28 February 1997, pp. 1293-5. Damasio’s somatic-marker hypothesis provides a more general framework for understanding such effects.
 Image search seems to involve a different emotional pattern than web search. See the recent talk of Peter Linsley, Google Image Search Product Manager.