[@Phoenix] I've waited months for an RP to catch interest, at least on the Old Guild. I haven't in this one simply because I had a small group of friends that I knew would love to RP with me. That said, I also had a LOT of RPs peter out and die due to lack of interest after it starts. Couple people drop, then bam, everyone else starts to follow. It's like a freaking plague, a cancer. Once it take hold it is hard to fight.

I think if you have a great idea that just doesn't take off, keep trying. There was one RP I tried to get going 3 times before it finally garnered enough interest to get off the ground. It was going good for a bit too, but eventually died. Still, it made it a ways past the very start, and that's farther than a lot of RPs go these days. Just keep trying, maybe modify your ideas if you think there is something turning people away--unless you are adamant about that particular thing. In which case, just keep trying. Eventually it will take off, if you wait long enough.

Also consider what section you are posting in. Obviously an advanced level RP will be a harder sell than casual, simply because a lot more people play casual vs advanced.