I track the activity to see what parts of the site people visit. I use this data to figure out how to expand the site. If people are interested in sports, I add more info about sports. If they are interested in history, I add more pages about history.
As for this new policy:
My advertising product seeks to replace advertisements from large national advertisers that track user activity with small local advertisers that do not.
So, while I think the demand that every site includes a privacy statement to be foolish, I am not adverse to using the page to sell a product. If advertisers bought their ads directly from sites, it would help replace ads from big advertisers that create user profiles with small sites that do not.