Buying SEO services is always a gamble, and to me it sucks that a service provider gets paid if their service is effectual or not. So about six months ago I signed up for a pay per rank service for 6 keywords that would be very valuable to me if I could get them. The service isn't cheap (the most expensive was $600 a month for #1-3) but it would still be profitable. However, after all this time absolutely NO serious movement has occurred, according to their charts they've had my sites pop up to the 50's-90's a couple times for a couple days. So obviously it doesn't cost me anything but I can't do any other linkbuilding to these sites/kw's as I'll end up paying them if I'm successful. Anyway, are there any pay per rank services with any redeeming qualities or are they all just suck like that?