Understand users by triangulating their needs with multiple methods
I think the key point is the fact that there is no ONE method of user research that will give you all the insight you need into your users. Instead, people should strive to assemble different research methodologies which balance one another in terms of their strengths and weaknesses.
Thinking off the top of my head at likely combinations there is:
1. Web site click-stream analysis and usability testing
2. Customer phone interviews and customer surveys
I'm sure there are a bunch of other combinations that my sleep deprived mind can't think of. Hmm... maybe there's a chapter or at least an article somewhere in that...