Regardless of the technical and privacy reasons for blocking, I just don't want to buy anything. I had no thought of a particular product before seeing the ad, and no thought afterword of buying it, despite its being just right for me.
I just don't want anything, other than food, clothes when mine wear out, and occasional specific purchases like a car or a book (that I knew I wanted on my own).
I think a big part of not wanting anything is that I don't watch cable or broadcast TV, just movies on Netflix or Vudu. I've inadvertently unconditioned myself from the purchase response. I'm almost sickened on the rare occasions when I see broadcast TV. "Really? I used to watch this constant, animated catalog of product? Bleah!"