There isn't really much to say that already hasn't been said (Well, try putting it in your sig like I do!), but a good way to get players without really having to advertise is to build up a network of players. Get to know other RPers, show them you're a cool dude. So when you make an RP, you'll have people you can depend on!

Also don't oversaturate your advertisement - it makes people want to even [i]click[/i] on your RP even less.