Can Affiliates be used on non-wpmudev plugins for commissions?

I've installed affiliates onto a photography sales site so that affiliates can make money from image downloads.

However, wpmudev didn't have a plugin to give me the photo-selling facility so I had to buy other software (wp photo seller).

Am I right in thinking that the affiliates plugin will only work with wpmudev plugins? (the ad-ons?) Or is there something I can do to set affiliate commissions?

Any help gratefully received.

Jane