Make sure each CCBill sponsor has IP Tracking switched on, if the cookie lasts over 3 days then IP Tracking is switched off.
http://yro.slashdot.org/story/13/02/..._medium=f eed
"Stanford researcher Jonathan Mayer has contributed a Firefox patch that will block third-party cookies by default. It's now on track to land in version 22. Kudos to Mozilla for protecting their users and being so open to community submissions. The initial response from the online advertising industry is unsurprisingly hostile and blustering, calling the move 'a nuclear first strike.'"
CCBill
"When the expiration value is greater than 3, no extra data will be logged to CCBill's database, so the cookie will be the only means of tracking a referred sale. If the surfer does not accept the cookie, the system will not be able to track them."