The arrangement is like pretty much every arrangement he engages in -- to reduce risk to zero so he doesn't have to spend a dime upfront on anything.
Lest we forget this is the same turd that then has the nerve to go and bitch about profits made by venture capitalists that did risk hundreds of millions of dollars by pumping them into Sirius when they saw an opportunity. If Howard "believed in the company" as he's so often claimed then he could have taken part in the opportunity by putting his own money on the line and would have been able to share in the returns. But no. As we all know by the bullshit like his insistence that XM subscribers belong to him, he wants it both ways - NO risk, ALL reward - and "everyone's out to get him" if anyone has a problem with it.