FWIW, they are ranked 18/33 traffic wise among Crypto sites and 5/9 among Crypto poker sites, according to Online Casino City.
http://online.casinocity.com/poker/betfair-poker/
And as you stated, only a fraction of their revenues come from online poker in the first place. It seems they contribute a relative pittance in revenues compared to the 20% haircut in market cap today.