I really don't know? There have been a few I have tried in the past, One offered Freeroll games where you won Points instead of cash and you could use the points to buy-into SnG games where you could win money or exchanged the Points for Cash on the Cashiers table but the exchange rate was Diabolical.
So I always used them for buy-ins, I built up a
bankroll of over £150 before they shut the
poker games down, and transferred all my money to their sister Sports betting site, It took a while to get my money from them through several E-Mails but got it eventually.
Their excuse was there was not enough interest in the Poker rooms and that was the reason they closed it down, Which I could understand as there were never more than 40 to 50 players in the
freerolls some nights less than that, So they were pretty easy to Win, I know, I used to win a lot of them.
One Site I really enjoyed was PKR.Com and they went Bankrupt years ago.