Google analytics, love it or hate it?
I have gone from loving it, way back, to hating it now. Why? There's two parts to it.
Firstly, most site managers use it for vanity purposes and up stream reporting NOT real decision making. For those purposes it is total overkill in terms of data collection.
Now, the second part, privacy. As a shop owner, if a company offered to GPS tag every visitor as they came through your door to tell you where they go in your shop you might find that useful. If the tag worked worldwide and the company joined that data with other shop data, making huge amounts of money from it would you force that on your customers?
I wouldn't.