The Ad

So there is a little ad right there on the right hand side of the page.  What I find interesting about it is it shows ads for things I do, have searched for or are interested in.  It is like it is enticing me to click on it.  Now how does it know that sometimes some places I do click on the little ad to the side?  Anyway we buy our electronics from Bestbuy.  The little woman and I love the fabfitfun boxes.  And we are going to Disneyland.  I just am amused by it.  And maybe a little scared.