In a survey on search, Google asked people how many results they would want by default; they responded that more is better, Mayer said. So the company conducted an experiment, providing some searchers with 30 default results. But it took, on average, a half-second longer to get those results than when the default was 10 results, she said. Out of frustration, people conducted fewer searches.A half-second increase in response time resulted in a large increase in frustration and consequent reduction in product usage.
"This indicated extreme unhappiness," Mayer said. "It was clear that we weren't going to make this change."
The anecdote also supports the notion that giving customers what they say they want is not always a good idea. Sometimes, you can't know what people want until you observe what they actually do, and what they like, in a given situation.