Not all ads are created equally sleazy. The privacy harms from surveillance ads, though real, are often hard to pin down. But there's another kind of ad – or "ad" that picks your pocket every time you use an ecommerce site.

This is the "sponsored listing" ad, which allows merchants to bid to be among the top-ranked items in response to your searches – whether or not their products are a good match for your query. These aren't "ads" in the way that, say, a Facebook ad is an ad. These are more #payola, a form of bribery that's actually a crime (but not when Amazon does it).

Amazon is the global champion of payola. It boasts of $31 billion in annual "ad" revenue. That's $31 billion that Amazon sellers have to recoup from you. But Amazon's use of "most favored nation" deals (which requires sellers to offer their lowest prices on Amazon) mean that you don't see those price-hikes because sellers raise their prices everywhere.