Xanthe, you are so well informed!!
Sure, I think there is room for a bookstore that specializes in erotica. I know Ellora's Cave is a publisher and someone who is choosing to self publish may not want to go that way. In addition, maybe they don't want hubby to know that their romance is something more involved than a Harlequin. Having your account on a site separate from Amazon or B&N is a boon there.