I just discovered Scott Jangro’s blog. Scott used to be with BeFree and was directly involved in the creation of the “Affiliate Code of Conduct” which is how the afsrc=1 parameter was born in order to help protect affiliate commissions from parasitic marketers who would otherwise overwrite the honest affiliate’s cookie and steal the commission. Scott writes:

What is this afsrc=1 parameter I see in reference to preventing other affiliates from stealing clicks? “First a little history. The afsrc=1 parameter was designed as part of the “Affiliate Code of Conduct”, a joint product of the then four major affiliate networks back in the Fall of 2002. By the time the code was released, Linkshare bailed out at the last minute (the only accurate way I can describe it) and Be Free, Commission Junction, and Performics remained. Since then, Be Free and Commission Junction have merged. Today’s Code of Conduct is still maintained by CJ and Performics.”

“It’s success can be debated forever, and I don’t wish to go there, but the spirit of the code of conduct was genuine (at least to me), which was to prevent one affiliate from stepping on another affiliate through use of any automated means (typically a software application that automatically clicked on behalf of the user). The intention was to putting this owness on the affiliates who were doing the stepping. In plain english, “If your software detects another affiliate in the mix, back off.”

This very in-depth article goes on to cover every question affiliates ask about how to place the code, if the parameter could break your website, do you need to put this parameter on regular affiliate links and much more. It also provides link to several other resources about the afsrc=1 parameter. Now I don’t even need to try to answer questions about this issue, I can just send affiliates to Scott’s blog - afsrc=1 Frequently Asked Questions (unofficial) » Jangro: Affiliate Marketing

Discuss afsrc1 and parasites at the 5 Star Forums