There is a software which I won't name but I was very surprised that they were charging $19.95 a month to be in their affiliate program. That seems kind of greedy considering you're helping their business. On top that, they don't tell you how much you will make per sale and if you cancel your $19.95 monthly fee, you can never rejoin the program. This is a reputable software company too.
In 99% of cases it's a scam. You shouldn't have to pay to join an affiliate program. Some programs have strict requirements with who they accept but you should never have to pay.
i don't believe it's right to pay to join. most reputable networks offer you to join free! it is the way it should be
You could join affiliate program for free. Why should you pay? Even yahoo let the affiliates join for free. I suggest you stay away from it.
It has to be a rip off. I have never seen an affiliate program charge you to be an affiliate. The goal is to get as many people as possible to market your product. Probably some scam to make up the cuts from commissions paid to affiliates. Not sure, but does raise a red flag.