Valve is not publicly traded.

In game micro transactions, all kids play Roblox and most games in Roblox require kids to spend money to partake in the activities of the server. And the currency is their own robux, which goes to the developers who made the game-modds.Roblox by it self is not a game, more of a platform to make games.

The developers can then withdraw their robux to real corrency but they take a 40% fee for that.

I'm not well vested in Roblox at all, but I know teachers and people who have middle aged kids, all of them are playing Roblox (the kids that is). On their ipads or computers, and parents buy them in-game currency to basically shut them up.

Take this with a huge grain of salt, because I'm going on hear-say, but that is the gist of it. Kids buy robux to play Roblox.