I'm pretty sure Heidi Montag has the worst selling debut of all time.
EDIT: Montag's album on Warner Bros. Records sold less than 1,000 copies in the first week(apparently 500 copies). Not sure why Jesse Camp is up there as worst selling debut album of all time.
Okay that's what I thought too, but I figured that was the self-released one. Maybe people are just trying to forget her so hard that she doesn't even count.