From how I understand your product, it sounds like it would allow people that buy a lot of items from company A to then use points from those purchases to get free items from company B.

If that's true, I don't think many companies would want to sign up for the service, since there's the potential that they might end up being "company B", which would mean that they'd be essentially paying "company A" and giving away items for free, and not getting anything in return.