Here in the 3rd world countries we don't have credit card unless we get a job, and when I say "get a job" I mean 28 and up . Morocco is very different from Europe and US because we don't have unemployement and just to make a living is really hard.
Also Piracy here is something commun because our ISP ( and we have only one lol who fuck the market with their High price and low value) Doesn't block torrent, as long as you stay out of Illegal stuffs...
Also even if I have a credit card at 21 ( I worked in a call center in the last summer so I can afford it) I will never lose money on apps. First: I'm poor Second : We only have 10 000 Dirhams ( 900 Euro ) to spend in a whole YEAR. Wich means we're very careful on what we spend money on.
So the best thing I can tell you is to add a banner and one or two Interstial ads and NOBODY will bat an eye .
Hope I gave you an insight OP :)