Yeah, I'm in this business... We call them stalker ads. It started on Google, and Bing is doing it now too. Essentially a cookie is set with various sites you visit (placed usually by the company, or affiliates to the company), and if you start to look at watches say at Amazon (wish lists etc), then as you move to other sites Google will start to place watch ads in front of you. Normally the cookies are set for 30 days. Then if you end up buying the watch somewhere, the last affiliate advertiser gets the credit for the click through. And ROI is proven for the ad spend. So by sharing these ads, we kind know what your into here!