When I was just new,a year ago I have promoted an affiliate program in Clicksure and spent some money and time to get a few sales. Since there is a minimum amount before I can get the commission($200 minimum If I remember it right), I spent 1 - 2 weeks promoting for it.
When I am about to reach the $200, my commissions was suddenly voided. The vendor says that those are fraudulent sales and cannot be considered. So I continued promoting and when I was again about to reach $200, the vendor voided my sales again.
This vendor is a d*ck and I was really frustrated so I did my research and found that I'm not the only affiliate that was scammed by that vendor. So I walked away empty handed after spending my time and money on that program.
I've learned my lessons, so before I promote for a product I do my due diligence and try to reach out to the vendor first. If he doesn't reply to me or they have poor support then I won't promote for that person.