With CCBill you know more what you are getting. But there can be a HUGE difference depending on the program you are promoting.
1. What cookie life are they using?
2. Do the tours have any leaks (clips4sale, etc)?
3. Any uncredited cascades or processors?
4. Is the default processor for typeins honoring your affiliate cookie?
5. What about cross sales (for rebills) ?
6. Are they updating? (rebills)
Some of the guys with 1:10,000 ratios are probably sending clicks when their affiliate ID isn't even showing up in the join form. Others are sending clicks to dead ccbill sponsors or those who switched completely to another processor. These will skew your global CCbill average. You've got to prune the bad ccbill sponsors regularly (at least once a year, better every six months). My CCbill average in 2010 is better than 2009 and currently about the same as 2007. But I'm pruning bad sponsors like a madman.
Daizzy has a great manual for affiliates here. It doesn't tell you everything but it tells you a lot:
http://www.signbucksdaily.com/marketing/ccbill-manual/