Here’s another piece to reinforce customer experimentation (doing stuff live with customers) versus customer research (doing focus groups, surveys, etc). This is from Jeff Jarvis in his book What Would Google Do?
Google vice president Marissa Mayer has said that Google is constantly trying to anticipate and interpret our desires so it can predict what we are going to do–our intent. It does that by watching our every move. When her team wonders whether a page should be this color or that, they don’t make the decision themselves, nor do they hold a focus group. They put both colors on the web in an A/B test that measures which yields better usage. “We’ll be able to scientifically and mathematically provide which one users seem to be responding to better,” Mayer told students at Stanford, demonstrating an engineer’s faith in numbers”.