For every game there should be a daily/weekly quest. You could get a certain amount of bananas from completing it, and maybe it would give you a badge the first time you complete one! The quests wouldn't be to hard, but not easy at the same time. For example, for CS:GO, you could have it be something like, "Defuse the bomb once in a competitive game." Then players would go off and try to complete it.
To be completely honest, I like this idea because then if players find a game that they like on this site, they can continue to earn bananas, and have fun at the same time!
Thanks for taking time out of your life to read this suggestion, have a nice day :)