The sad truth is that most people who join an RP are unaware of the commitment involved, or expect daily posts to interact with. I have the most luck trying to rally together people who I'm on the same wave length with and RP with the lot of them. That's not to say some randoms aren't dedicated, but you need to plan on at least a few of them dropping out or getting busy. I actually think the commitment problem is compounded in this type of environment because a new RP starts up every ten minutes.