Hey there,
Give your JV partners something that other people aren't offering, and be creative. If you were them, what would YOU want, besides commissions?
Some ideas:
1) You could put a permanent message reviewing their product in your autoresponder series.
2) You could promote THEIR affiliate program in your download area.
3) You could put a free viral report or audio of theirs in your download area, sending them traffic.
4) You could introduce them to other internet marketers and potential JV partners.
I'm sure you could get off the ground without a huge list if you offered them good value like this.
And of course, make sure that your product fits their list and benefits their subscribers.
Hope that helps,
Sam