They claim 260 million members, paid subscriber list of 1.2 million. I'd guess that means 260M profiles since the sites were started, doesn't say if the 1.2M paid subscibers are still paying or just paid at one point and are still in the database.
A little under $2.00 per member, around $416.67 per paid subscriber at 500M.
Seem like a reasonable valuation?