Reading the other comments really gets the creative juices flowing. My idea definitely builds on the 'thinking outside of the box' ideas.
Maybe a loyalty scheme of some sort would help retention on the platform. I'm thinking similar to the Xbox achievements type set up when you can earn badges as a developer and a customer which allow everyone to earn rewards, be it monetary or something else. For example, rate 5 games, earn the Mates Rates badge and earn $X to spend in the store. Then these accounts can use these badges to display next to their names on the forum/discord/etc as like a badge of honor.
I'm sure the idea would need refining but I'm thinking something like this would be more beneficial for indie devs who all want to support each other.