Number of times I've clicked on an ad over the past 20 years or so and bought somthing on the click-through somewhere? One or two, maybe three, times.
Number of times I've bought something (an airline ticket, a hotel room, a magazine, some clothing, a device, etc) and have had an ad for that very thing displayed to me everywhere I go (Facebook, Google, Fandango, etc) for a week after having already made the purchase? A couple of thousand times.
The ad tech infrastructure seems very good at targeting me *after* I've already purchased. This is _exactly_ when you do _not_ want to be spending ad dollars as a corporation.
Why does this happen?