They've improved this year for me. They claimed to be stepping up anti-piracy efforts. I dropped them earlier from my active promotion but when the ratio improved I put up some new links.
2011 - 1:1500
2010 - 1:5000
2009 - 1:1300
It's not just the site. It's the traffic-site match. If you have long tail key phrases I suggest identifying them and if possible targeting a pre-sell effort using the key phrases. Make sure you let the surfer know that what they are looking for is actually inside that site. Especially if it may not be obvious from the tour. You might try your own special tour targeting the key phrase linking it directly to the join page.
