Gwern's Law: Ads cost you a tenth of your users
I believe it. There are a lot of games that I downloaded from the app store and really liked initially. However, I noticed a pattern. At first, ads seemed to be optional (i.e double your gems by watching an ad!) However, after about 10 minutes of playing, I'd see an ad. No big deal. But then it got more and more aggressive. Pretty soon there was an ad after every single level, (plus the bonus ad if you want to double gems). It got to the point I was spending about 50% of the time actually playing games, 50% of the time watching ads (the levels could be beaten in 30 seconds or so).At that point I uninstall even though the game is fun. It's not like I can just pay a 1 time fee to get rid of all ads with the type of game I am talking about. I have paid to get rid of ads for a few bucks in the past, but these games will still pester you with in game pop-ups for "diamond memberships" (outrageous recurring subscription fee for nominal and significant bonuses) and "best value" gem packs (also sold at outrageous prices going up to $100 for the biggest pack).