You look at a pair of boots once and then see those boots on every site you visit for two weeks. How does that happen, and can you actually stop it?

Why It Happens

The boots followed you because a tracker was placed on the page you visited. That tracker writes a cookie or an identifier tied to your browser, and ad networks use the identifier to show related ads elsewhere. Nothing mystical. It is a small file and a database.

Steps That Actually Reduce It

1. Turn on tracking prevention in your browser. Every major browser has a strict setting now. Use it. This blocks the biggest trackers by default.
2. Clear cookies for shopping sites after you shop. Site specific clearing, not the nuclear option, so you stay logged in where you want to be.
3. Turn off ad personalization in your Google account and your phone settings. This does not remove ads. It removes the creepy relevance.
4. Use a separate browser for shopping and keep it logged out of everything else. Cheap solution, very effective.

What Does Not Work

Incognito mode alone does not stop trackers on the sites you visit while you are browsing. It just forgets them when you close the window. And a VPN changes your location signal, not your browser identifier, so the ads keep following.

I do the split browser thing now. Shopping happens in one window that never logs into anything, and the boots stopped turning up everywhere within a couple of weeks.