SirPrimalform: They're doing a pretty awful job of marketing the site... and the fact that they include so many Steam keys in IndieRoyales means they're just sending everyone to Valve.
That, and their DRM-free reputation has taken a bit of a knock of late with a number of titles that have imposed DRM even from Desura. There have a number of games that only gave you a Steam key from Desura and didn't announce this (although this has since been changed), and a number of games which had their own form of DRM and didn't announce this fact (Depth Hunter).
I know that I for one have been a little wary about buying from Desura since, even though the service itself is awesome.