"This guy has a vacuum cleaner. Let's recommend him more vacuum cleaners to buy!"
Even though every single one of the platforms claim to be using cutting edge tech for targeted ads but all of them suck. I don't see them improving even if you give them a guided tour of your home including closets
More info - https://news.ycombinator.com/item?id=14755498
In other words, you use your phone's camera to do whatever, and the phone notices you linger at a window or a billboard (by tracking your eye movements and retinal responses.) You get home, and suggested items are virtually added to your living room.
Maybe you walk past a clothing store and it adds a new suit to your reflection.
Or AR games that require you to move past physical ads or storefronts, and take pictures of them.
There can be good utility for ads without being dystopian. Like furniture sets you want buy to preview in your new empty apartment - not items you are totally uninterested in buying. I'm sure there will be countless ideas to get ads on AR pretty soon that will be unaggressive and jive well psychologically
So Facebook can see what's in your house and on your body and deliver those relevant, targeted ads you so dearly crave.