The focus should be on making a profit, while respecting peoples privacy.
Honestly I don't see the value of tracking though. I tried running my browser without Ghostery recently. The "tracked" ads are generally pretty poorly targeted. I got a lot of ads for TransIP after browsing their price plans, but that's sort of the wrong time, at this point I'm already aware of them.
Amazons recommendations are pretty good for books, but not much more than that and that's despite them having huge amounts of data.
So why the need to track me, if you can't do anything useful with it?
It's not a technical problem at all. Tracking is as easy to solve as to put a UID to each device (problem solved).
e.g. Apple some time ago forbid developer to use such an unique id (http://www.tuaw.com/2011/08/19/ios-5-deprecates-udid-as-iden...) probably on privacy laws grounds.