This probably won't be a popular reply, but it's a true and honest one.
I've tended to promote, and encourage my clients to promote, based upon the relationship with the JV Parnter and affiliate and not with regad to the product for the most part.
I base this simply on the value of the relationship.
In the Forex business, for example, a great customer is worth about $600 to me once you figure out my products that they buy, plus the affiliate commissions I get. Even a "bad" affiliate is worth 8 to 10 new buyers, and a good one is can be worth six figures on each launch.
For me it simply comes down to the math and what relationship is worth the most. Like I said, probably not the most popular answer with people, and it's also one thats easy to misread, but it's a true answer.