i have received few invitations from combined poker/casino operators with free money offers, 10$ or so, to play in their casino.
i started with some winnings and asked about transferring of winnings to my poker account.
and answer was that i need to play for 50 times increased funds before "withdrawal"
and i have played (normally for free) and lost everything.
so, i always have on my mind "when You play poker, You are playing against others (people) and when You play at casino, You are playing against "them" (house/operators).