It can be very erratic. My site
www.glamourimages.net can have several fantastic days then an absolute disaster for no apparent reason! Had one last Tuesday in fact - 10% of sign up levels compared with a normal day. I find that on these bad days, clicks out are at ludicrously low levels, completely out of character with a normal day. It's almost like nothing is being recorded by CCBill.
I have taken this up with them but always get the same "nothing wrong here" stonewall answer. The simple fact is that they daren't admit to anything as the fear of litigation from the "big boys" means denial is the only option.
I guess we just all have to accept a glitch from time to time even though it pisses us off!