I'm not sure if C2 will ever have a multiplayer option (I'd love one!), but you could rent out a small amount of server space and bandwidth for users to test out the multiplayer options.
Users who don't have a server can create a game or try out the function without having to rent a whole server and setting up the whole thing. (And for testing purposes, they don't need a lot of server bandwidth and space and probably don't need to connect more than 2 computers).
In return, you could ask for a monthly fee or something like that.
The profile idea sounds pretty good. It'd also be a good idea to show off a few awesome games made with C2. To give people an idea of what they can do with the engine.