Hi James,
My company is UK based and last autumn I set up our affiliate program.
I spent the better part of the summer researching into affiliate programs, especially focusing on the benefits/pitfalls of in-house V's external programs.
I decided that the best way to go for my company was in-house, as though slightly more labour intensive it allowed us to offer more commission, develop closer ties and be more supportive to our resellers/affiliates.
Also, I was conscious that although these external programs may have 1000's of members you have to consider who and how many of these members really will be interested in and/or 'sell' your product.
There are many programs out there that do have a good reputation and I have spoken directly with a number of them myself and found them to be very helpful.
I guess what I am trying to say in a nutshell is:
1. Do your research on whether in-house or external is the right way to go for you
2. Create a list of questions and contact all the companies directly with this - monitor how quickly and throroughly they come back to you.
3. Obtain further feedback from the forums
If you require further info on running an in-house program, feel free to come back to me at any time. You can also take a look at the program I've put in place for my company at
http://www.depositit.com/reseller.shtml
Good luck and enjoy the rest of the long easter weekend!
Anthony