I was blown away by this story. Timothy Ferriss was writing a self-help career book and wondered which of several titles would appeal to the greatest number of readers. Most authors (and publishers) make such decisions by gut instinct or, perhaps, by soliciting opinions from a few friends. Ferriss decided instead to take a leaf from "real" businesses and actually conduct market research. He created Google Adwords campaigns for several possible titles, including "Broadband and White Sand," "Millionaire Chameleon," and "The 4-Hour Workweek." By running each of these campaigns on Google for a week and seeing which title attracted the most click-throughs, he determined that "The 4-Hour Workweek" was a potential winner. He published the book with that title, and it went on to be a major bestseller.
Cost of this research program? $200.
In book publishing, we tend to assume that success is a matter either of luck or of sheer ineffable instinct, which you either have or you don't. Stories like this suggest to me that we could probably achieve success a lot more often if we used our ingenuity to find ways of pre-testing our ideas.