Why do I see ads for apps that I have installed?

Question

When I'm using my (Andorid) phone I keep seeing recurring ads for Whatsapp, Tiktok, Deliveroo, etc..I have these apps installed, and some of them I use daily. So I'm wondering if the targeting is explicit or is just a mistake?I see only 2 scenarios:- The ad targeting system can't see that I have these apps installed (Good i guess in terms of privacy)- The ad system can see that I have the apps, but the companies still pushing their ads (waste of money?)Does anyone here have any domain knowledge about these kind of ads?

helph67 · Accepted Answer

This page may be helpful, particularly the information about uBlock Origin. https://github.com/aronmolnar/smartphone-hardening-guide

legrande · Answer

It's not hard to connect usage of an app to ad-tech systems. When you run those apps, they have ad-tech built into them, and pass on the fact you are using an app to the ad-tech companies.