What's the best way to split-test affiliate pages? My big question is how to figure out which version is converting better when the conversion page is not on your site. I know that Affiliate Radar and such programs can match up affiliate network conversions with keywords, but I'm not sure how to also factor in the variable of landing page variations. One obvious solution is just to try to track at least click-throughs to the merchant site even if you can't track conversions; would it be possible to track conversions by redirecting the affiliate link through an automatically refreshing page?
Depends on your affiliate software and what testing software you use. Most testing programs just use code on the landing page to swap pieces of content in/out. Most affiliate tracing software simply gives a cookie whenever the page is loaded, so there shouldn't be any conflict. That being said, you're probably looking at getting mutli-variant tracking software to do what you want, which is a fairly complication thing to learn, but very well worth it.