Nice if you are seeing them as an additional source of revenue I guess. Bit pricey otherwise.
Just to settle my completionist tendencies - here are the affiliate reporting systems I found and looked at:
nifty stats : $20/month. Looked very much like aff meter. Couldn't verify which programs were supported so haven't looked at this any further
aff meter : $15/month. Didn't seem to handle the differences between pending and confirmed transations very well. Very slow to use if lots of individual transactions
affjet : Looks interesting, but won't tell you pricing until you've signed up (even if you ask), which is dodgy in my book.
stats remote : $30/month - can install on mulitple systems as long as you use 1 at a time. looks interesting - will be coming back to this
Might give affjet a shout in a few weeks. Apparently they are nearly ready to announce pricing ! (Funny - seems to have been running for some time - pretty sure I contacted them with the same question 2 years ago). Would prefer a SAAS service really to save downloading data to multiple systems.