Some Epoch sponsors running
http://EpochStats.com/webmasters/ back-end haven't set their join forms correct and affiliates aren't credited for sales. You should contact the program if you are promoting it.
The correct join form link looks like this one
https://sales.epochstats.com/signup/...892&p=8832&c=0
There are other ways to get Epoch join forms for paysites, but they aren't supported by EpochStats tracking system in terms of affiliate promotion.
Find the list of broken EpochStats sponsors at Signbucks