TPG sold when the site was a lot smaller, $15m is the price that is generally discussed in the industry.
$20m would seem fairly low for MMS. The nearest quoted UK comparator to Bankrate is on 20x EBITDA - I'm sure someone can tell me what the Bankrate MBO deal was done at - so you would want that as a purchase price after factoring in a 25% private company discount. That would imply $1.3m of profits. At an average of $200 commission per card that would only imply 18 applications per day (assuming revenue = profit which in blogworld it pretty much does, even with full time staff as I have).
Or, in reverse:
18 cards per day at $200 commission = $3600
365 days per year = $1.3m
Assume revenue = profit for simplicity
Sell for 15 x earnings = $20m
But 18 apps per day feels low ....