I found a datingsite that doesn't work with lists of profiles, but instead matches up people for "speeddates", where they get to chat anonymously for 5-10 minutes and then decide if it's a "match" (photos become visible gradually).
It works with a system of gender-specific invites that members can send to other people, and to keep it balanced there are hardly any invites for men, while there are almost unlimited invites for women.
Plus, it's free, and makes money from ads instead of subscriptions.
I predict that this thing will grow HUGE.
www.paiq.nl (it's in dutch, and since you don't have an invite, it's probably not of much use to you)