I know a fair bit about this space as worked marketing large mobile games globally for an ad network. On a large scale you're right, the big guys use all the mobile ad network channels so paid media and the occasional featured spot on the Apple app store as a result of the paid media, so it's Chicken and the egg.
That being said if you're just starting out on a "low scale" I would really focus on Facebook ads and mastering this as an ad platform. You could always approach a large app "publisher" who work with indie developers and they cross promote it in their games and you receive a cut of the revenue
Also, in terms of monetising your game, a lot of games are monetised through featuring video and banner ads and not in-app purchases which only a small percentage of free to play users do.
I've read some great posts on this forum, so hope that helps give some direction and good to be able to give something back too.
That being said if you're just starting out on a "low scale" I would really focus on Facebook ads and mastering this as an ad platform. You could always approach a large app "publisher" who work with indie developers and they cross promote it in their games and you receive a cut of the revenue
Also, in terms of monetising your game, a lot of games are monetised through featuring video and banner ads and not in-app purchases which only a small percentage of free to play users do.
I've read some great posts on this forum, so hope that helps give some direction and good to be able to give something back too.