As far as I was aware Betdaq pay all the software vendors to provide their Betdaq products for free and possibly have a revenue share in their too like an affiliate type thing, that's why many promotions are usually web site only, Betfair used to do similar where they'd waive the commercial charges to anyone providing an API app for free, that was one of the reasons certain software got a large userbase quickly before charging.
I've no idea if what Betdaq pay cover the charges fully or give a decent return but none of the vendors are providing Betdaq software out of the goodness of their hearts.