I would just like to add.. if its still unclear - both tracking methods work 100%, but using them both means you'll get commision WHENEVER the sale happens (member upgrades to VIP), classic ccbill link would only track it for the cookie duration period.
Also, it is very easy to test any of it with ccbill support if needed
Also worth repeating - I'm more than willing to further clarify anything if needed, hit me up mail / icq / skype / msn / pidgeon currier.