I have the same experience. On my machine, only Safari is "vanilla" - other browsers have various levels of ad/js blocking. So the only time I see ads is in Safari. I can't believe they're still feeding me Newegg ads for components that I already own and have bought from Newegg. I understand that's not as trivial a problem as it sounds, but I can't help but think companies are overpaying for ads.

i have friends who work for retargeting ad-tech companies. That's those firms that bid for and deliver ads for things you just maybe bought.

The deal is those ads show up when the ad space is the cheapest. It's known as remant inventory. So the retargeters can pick it up for very cheap.

The deal is the companies KNOW that some people see ads for things they already bought. But some people are seeing ads for things like only considered, and bombarding them with ads does affect behavior. The question is, is the increase in revenue worth the cost of retargeting.

The answer is very much yes. Even as it annoys people who already bought it, which doesn't even factor since they already made the revenue from your purchase.

To be fair, Google is in the business of making money on ads. If the customer wants to throw money on a stupid ad buy, then that's not particularly their concern.

Yep, Google does this exact same thing. I search, I buy, and only then I see ads for a product I already own.

It's just as likely that they have done extensive testing and found out that for whatever reason, ads for products you already own still encourage you to buy other stuff.

A lot of assumptions we make don't hold up when you start gathering real data.