Looks like Douglas Bowman was right and its only got worse since he bailed.
http://stopdesign.com/archive/2009/03/20/goodbye-google.html
data is important, but it only gets you so far: table stakes. the thing that differentiates us is the ability to use intuition.
don't forget that your "gut" has been developed over millions of years of evolution to keep you alive, and its done a pretty good job. playing with numbers? couple thousand?
For instance, a fast food chain might take some data and find that they can decrease the quality of their ingredients without immediately loosing customers because people have habits and don't really notice right away (and because consumers will chalk up a few bad experiences to variance at a place they know well). But, over time, the chain develops a reputation for lower-quality food, and customers slowly leave.
The problem with this example is that the data can easily measure long-term effects, especially the subtle damage to reputation. This is a case where intuition may be needed to override data.
But where's the similar example with Google?