The problem I have with many freemium games is for me they have absolutely no lasting appeal. I would estimate that 75% of freemium games I've installed, I may have played a sum total of half an hour and then got annoyed/fed up/bored and removed it. Adverts, replay timers etc. are certainly to blame but what mostly is a turn off for games of these types is there is no soul in a lot of these games.
Take Triple Jump, Don't Step On The White Tile, Avoid The Blocks etc. for example(s). They're like Christmas cracker toys. You play them once or twice, discover how lame they are and throw them away.
While I realise those games aren't meant to be much more than that (and an SEO exercise), there are so many like these on the various app stores and few games that have any kind of depth to them. I would more than happily, and have happily, paid $1, $2 or more for a game that held my interest for longer than half an hour. The biggest problem I have is these throw-away games have been so cleverly marketed or SE-optimised that they make up the bulk of "featured", "highlighted" or "best selling" games and any game with a modicum of depth disappear into the ether, undiscovered. It's frustrating for someone who wants to play a fun, entertaining game, not an annoying, repetitive and uninspiring christmas cracker game.