Great read over on the Freakonomics blog with Bill James, the data wizard for the Boston Red Sox. A few choice quotes rang true for me; he could have been talking about web analytics:

I would say generally that baseball statistics are always trying to mislead you, and that it is a constant battle not to be misled by them.

…

We haven’t figured out anything yet. A hundred years from now, we won’t have begun to have the game figured out.

and to who should have a larger role in player evaluations, scouts or stats guys:

Ninety-five percent scouts, five percent stats. […] the knowledge of who will improve is vastly more important than the knowledge of who is good. Stats can tell you who is good, but they’re almost 100 percent useless when it comes to who will improve.