The United States is the capital of review mania. The need for feedback and affirmation is “a very American thing,” said Gerd Leonhard, a Zurich-based self-described futurist, book author and corporate consultant. “Europeans don’t do this; we’re not gung-ho to write reviews, and many people will refuse.”

“We’re now into review begging, which is equal to a barista expecting a tip,” Mr. Levine said, calling the practice time tipping: I already paid you, and now you’re asking me to pay you more, in the form of a review. “If you want a review, then pay me for my feedback,” Mr. Levine said.

“The attraction of slobbering attention is deep in our soul,” Mr. Thompson said. “It’s not a question of everyone getting our 15 minutes of fame. It’s me getting it and not you.”

In the past, Consumer Reports, a ratings magazine, was the source for consumers looking for the best products and services. Today, many people rely on readily available... See more