Good point Must. But I don't know that margins are so large . For $22 a month, they gotsta mail me all the DVDs I can use and return (3 max at a time). I can't see there being a large margin in there for steady users. Of course, there are plenty who probably hardly use it, and pay anyway.
Low barrier to entry and all.. it 's just a kookie business. Maybe better if they weren't pure , but a small part of some other large company.