I read something before about how if you've bought a vacuum cleaner, maybe there is an issue and you return it, so you are still more likely than a random person in purchasing one again soon. Not sure if there's ant truth in that. Maybe all that matters is that you might click the ad out of curiosity as you were recently looking into them...

> maybe there is an issue and you return it, so you are still more likely than a random person in purchasing one again soon

I find it hard to believe that return rates are high enough for this to be worth the trouble. It's much easier to believe that the advertisers are simply reacting to any signal for personalization, even if they received that signal too late.

> Maybe all that matters is that you might click the ad out of curiosity as you were recently looking into them

That serves the interests of Google or any other ad network; they don't really care about whether you eventually complete the purchase, as long as they get paid for your click. But the company actually selling vacuum cleaners should care.

Indeed. It might also be the case that the advertisements are tailored to the weaknesses of the product you bought, such that in case of a defect you might consciously or subconsciously remember the advertised vacuum cleaners with different properties.