So, minecraft has become a large phenomenon due to the simplicity and ease of the game. It has taken the entirety of 'do-it yourself' to create an unlimited amount of replay value with very little effort on the creator's end. You can even set up servers and play with your friends. But, there are ways to make minecraft even more fun then playing on a server with your friends, playing on a modded server with your friends. This allows you do add mods which enable players to do pretty much anything they want with the server. I recently got commissioned to set up a minecraft mod server. It was not a big job and if I ever do it again it would take me an hour or less if the server computer was already constructed, and I did get a pretty penny. So if you a looking for a quick buck and you are a computer programmer who is familiar with networking, try setting up a server or a mod-server, there is very little documentation on how to do this so it might take you a while the first time.
The worst part about this game is that it runs on Java, this is so it can be portable. As a result of java and programming habits of the developers, users on the minecraft server are expected to have a whopping 133MB of RAM available to them, the server will still work with less but may slow or crawl. A nice old Pentium III or IV computer will probably be able to support two players on a server. You need a pretty beefy computer to run alot of people.
Anyways, if you are looking for a job see if any of your friends want a minecraft server. if you have an extra one laying around charge them setup and a monthly fee if they are using their own, charge a larger setup. And if you don't have a minecraft account make you client pay for it instead of yourself.
I will never spend a dime on minecraft!
-Aeon