> To _really_ try and test this, you could download the Facebook (or Amazon or whatever) app, and (within earshot of your phone) consistently talk about some co

> To _really_ try and test this, you could download the Facebook (or Amazon or whatever) app, and (within earshot of your phone) consistently talk about some completely random purchaseable item that you have no intent to purchase and have never otherwise indicated you have an interest in. Chances are you will not get ads for it. That's the trick isn't it. How do you choose a random purchasable item without indicating interest in. Is it because it was something you saw recently, but don't want to buy? How many (targetting) similar people near you also saw that and may want to buy? How much is that ad being shown to you now, but you hadn't noticed because you weren't interested in the product? It's certainly possible to carefully craft an experiment, but it's not easy. And a poorly crafted expirement won't show much.