A good JV is someone who will always promote for you, (regardless of how good your product is) because they know you're always going to promote for them. Obviously it helps enormously if you both have great products, but its the relationship which counts far more than the product does.

By the way , you need to revise your commission percentages. Start at 50% and keep going up to 80%. You need to attract JV's and offering high commissions will help.