Well I'd have to say in many cases, it's mostly the revenue from rebills. Dating sites rebill great
Some I'm sure are also making extra cash from upsells of complimentary products (ie. herbal, toys, dvds, etc...) - however this can fluctuate and I wouldn't use it as a base for determining payouts.
Basically it's simple math. For example, our Pay-per-Profile pays $50 per signup if you calculate any level in the scale (ie. 1:50 gives you $1.00, which means $50 per paid signup).
Now if we charge $24.95/mth, we obviously know our average conversion is > 2 months or we wouldn't be making any money
