I got an email last night saying sign up with the code POSH5 for free £5 to play with.
There weren't many games running then (2am) so I just bought tickets in all the rooms and went to make a cuppa...came back and I had £20! :P
....Then I lost it on Blackjack!
NB: Winnings can only be withdrawn after an initial deposit.
Code: Posh10 for £10
UPDATE: If it doesn't work then try using the code 'Posh5' instead, as that one gives you...yep...£5 :)