discussions

When others comment, like and respond to your discussions/comments, you get paid. When you comment on their discussions they get paid but you get noticed and the favors will be returned to you. It is a two way street. The more you interact on others posts, the more they will interact on yours. Everybody wins.

Earnings depend entirely on how much interaction (that is, responses, comments, likes &c) what you post gets from other users. Whatever you post - a discussion, a response to someone else's discussion or a comment on a response/comment in your own or someone else's discussion - becomes eligible for earnings but it doesn't actually earn anything until someone else interacts with it in some way.