Oh, I don't care about money at all, I just do this for fun, but it's something I noticed with admobs and thought it was annoying and clearly a pattern.
I was thinking maybe Google has a system to make sure new accounts have a certain limit for each month and then at the end of the month, they would check if the hits are genuine and raise the limit a little bit.
My other two apps are games, that's my main hobby and that's what I focus on, I made a companion app because it was for a game that I really love close to my heart and there wasn't any companion app for it so I thought it would be a good reason for me to do it and test my skills from game design to app design.