[mmanfrin]

Your anecdote is not emblematic of the whole. Many people do not immediately buy big ticket items they look at online; but there is data that shows repeated marketing of a product works, and works especially well when the merchant already knows you were looking at a specific product.

Yes, this means they end up wasting ads on people who already purchased, but that is outweighed by the other portion of people who didnt already purchase the product.