Ads on android

I don't get them but I see others do? I also see that there's a new update on iOS that really monetized it and took away lingots in exchange for gems?

Am I just lucky that I don't get them because of some bug or should I expect the app to become ruined in the next few months with shitty ads? Because as it is, for a beginner learning Spanish, it is brilliant. I don't mind paying a small fee, but if they're going to ruin it with ads and then overcharge I don't think it's worth the effort and will switch to babbel.

Anyone know what the story is? I'm using latest version of app on latest version of Android.