This is just a guess, but I suspect it wouldn't be in The Google's best interest for other engineering departments to be too involved with the ones that deal wi

This is just a guess, but I suspect it wouldn't be in The Google's best interest for other engineering departments to be too involved with the ones that deal with data mining, otherwise they'll end up knowing too much. Even if someone working on a particular web product at The Google thought it would be a good idea to use the existing tracking to improve the user experience, I imagine there would be so much organizational friction in place that they're likely to give up.