Consider an ordinary morning. You open the news and read coverage of yesterday’s debate that supports the political views you already hold. An advertisement reminds you of something you were thinking about buying. A recommended video explains why people like you are right to be worried. A political message speaks directly to the thing you most want somebody to fix.
Your newsfeed and inbox can surround you with information chosen to match—and sometimes reinforce—your preferences.
None of this targeting required sophisticated AI. Publishers chose audiences, advertisers chose customers, and platforms chose what came next. Remembering our interests made many of those services better. The concern is what happens when keeping us pleased becomes more important than showing us something that would make us reconsider.
That concern begins with a familiar human preference: we often seek information that justifies a choice we have made or are preparing to make.1 Businesses can serve that preference with reassurance. This chapter follows it through purchases; the next chapter takes it into news.
From surveying to justifying
We've all done it. You have to make a major purchase—a car, a house, a dishwasher. You compare websites, keep a few models open in different tabs, perhaps visit a store. You want to know which option holds up.
Something catches your eye: a model with a clean look and a 4.6-star rating. Are the reviews real? How many people contributed to that rating? What do the negative reviews say? As you look, you decide which features matter, which compromises you can live with, and whose reviews you trust.
Then you find a favorite. You have not bought it, and you are still reading, but now you want confirmation. A favorable review reassures you. An unfavorable one makes you question the reviewer: did they install it correctly, was theirs an older model, do satisfied owners bother to write reviews? Those can be fair questions. The problem is that you may not question the praise as closely. Your survey has become a search for justification, perhaps without your noticing the change.
A favorite changes the comparison
In “Predecisional Distortion of Product Information” (1998), J. Edward Russo, Margaret G. Meloy, and Victoria Husted Medvec reported two experiments in which participants received information about two hypothetical brands, one feature at a time. Once a brand became their favorite, they interpreted later information in its favor. When the favorite changed, the bias shifted to the new leader.2
A tentative preference could influence judgment while the comparison was still underway. But did participants notice that influence? Recognizing a favorite is different from recognizing that you are giving it an easier hearing. The experiments did not establish when someone became aware of that shift.
Russo and Anne-Sophie Chaxel examined the question further in “How Persuasive Messages Can Influence Behavior Without Awareness” (2010). Ads gave one of two holiday resorts an early advantage; participants then interpreted factual information in its favor and were more likely to choose it than participants who saw no ads. Their ratings gave the researchers no evidence that they recognized this indirect influence.3 The choices were experimental, not paid bookings. Even so, the result helps explain why a seller would want to establish a favorite before the customer finishes comparing.
Wow, you made such a great decision
After the purchase, reassurance has another job. An advertisement praising your new car can help you enjoy the decision you made, even if you have no regrets. It speaks to owners as well as prospective buyers.
In “Postdecision Exposure to Relevant Information” (1957), Danuta Ehrlich and her colleagues compared recent new-car buyers with people driving cars at least three years old. Recent buyers reported reading more advertisements for their chosen brand than for brands they had rejected or never considered. The other owners showed a weaker preference for advertisements about their own brand. The researchers interpreted the pattern as an attempt to reduce doubts after an important decision.4
Confirmation can be pleasant; it can also ease cognitive dissonance, the discomfort of holding conflicting thoughts. You may love your car while still thinking about the better mileage of the model you passed over. Praise for your car's strengths can make that trade-off feel worthwhile.5 The useful question is whether the next advertisement adds information or mainly helps you feel better about the purchase.
Marketers have studied that opportunity for decades. James F. Engel’s “Are Automobile Purchasers Dissonant Consumers?” (1963) discussed advertisers’ responsibility to recent buyers. Shelby D. Hunt’s “Post-transaction Communications and Dissonance Reduction” (1970) evaluated retailer communications intended to reduce doubts after a sale.67 The research question extended beyond winning a customer to helping that customer remain comfortable with the choice.
Present-day guidance carries the same idea into online shopping. Convertize recommends reassuring buyers on the confirmation page and in a follow-up email, with satisfaction and repeat purchases as the intended benefits.8 A welcome email can help you get started and reward you with the feeling of having chosen well. Both can serve the seller as well as the buyer.
So the next time a dealership congratulates you on a great decision, read the message as you would an AI assistant congratulating you on a good idea. What supports the praise? Would the source tell you if the decision needed another look? “The customer is always right” is a comforting rule for a business that wants the customer to return.