How to advertise an application in AdMob and is it necessary?

Question

Google AdMob

Hello! Perhaps my question seems stupid, but I'll risk asking it :)

I tried in every possible way to drive the subject itself into Google, but all the articles and information are only about how to push this admob into your application and make money on it. I could not find information on how to actually get there and advertise my product? Enlighten, please ...

Well, in general, there are those who use it? Is there any point in going there? Thank you.