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.”

“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

“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.