This is basically how advertising works. You're using most likely several, free, ad supported websites or apps. Instead of paying for the app you're using, you'

This is basically how advertising works. You're using most likely several, free, ad supported websites or apps. Instead of paying for the app you're using, you're compensating the developer with your attention on ads and the developer is then paid based on that. Instead of directly getting money for hearing pitches or being the subject of cold calls, you get to use free services.