ROBLOX is one of the biggest online games out there, where you can program and make your own games to share with the community. There aren't many tutorials online on how to learn LUA (and if I'm not wrong LUA is modified for ROBLOX), there are YouTube tutorials, even a wiki. But those are the only sources. Many people have tried to make a game on ROBLOX, but they simply can't due to the fact that the LUA is one of the hardest languages to find on the internet.
Not only for this platform called Roblox, but for many other applications.
Talking about money, there are many kids out there willing to pay to learn LUA just so they can make their own games in ROBLOX.