I really can't tell what could be the right way, but I definitely can tell two ways to avoid like the plague:
1) Zynga way: crappy or repetitive games that trigger and exploit obsessive-compulsive behaviours
2) EA way: ruining games that could even be very good with a bad transaction system (spending almost all the rarest and hardest earned kind of game currency, very slow to earn playing, expensive to buy with real money, by mistake, hitting the wrong button and not being asked for confirmation, made me hate Real Racing 3, that I quite liked despite some flaws, so much that I stopped playing it altogether. I'm still mad with EA for the time lost, and had I spent money for that game gold, I'd be even madder. Surely after this experience, even if I'll eventually forgive EA, I won't trust it anymore on its F2P games.







