Who do you think would be an easier sell for a new TV in real life--the person at BestBuy who just looked at flat screen TVs for 25 minutes or someone random off the street?

Wow! This is unfortunate because that person has now been primed for that gift. If it's a fairly obscure product that it was possible they hadn't heard of, then they may not be as surprised upon receiving it, and either way if they are able to remember they saw it while you were browsing facebook, they may be less convinced of the genuineness of the gift, thinking you just clicked on whatever ad jumped out at you rather than using your creativity to select something.

Even worse, if it's an obscure product that suits their taste, there's a chance they could decide to order it after seeing that ad!

They get 4X better CTR than other ads, and decent conversion. Even if they don't work for >99% of people, they can still be profitable.

> I looked at a product and either decided to get it or not. Why are you still showing it to me? I'm done with that product.

Especially annoying when I bought the product, and I still get ads for it.

sometimes I'll look up a product passively (someone mentions it on a site and I google it), but don't really look at the page long enough to think about whether to buy or not buy it (a specific instance of the more general "tabbed browsing has made me open tabs I don't look at")

these ads are probably targeting behaviors such as this, more than "decided not to buy"