I really think that you should add a feature to give free chips directly from the website.
Something like 0.00001 chip, that has the value of 0.00000001 * 100 chips. ( it's like zero value ... but it is enough to play )
Then the user can ask for the free chip more than one time every 3/4 days, and only if he has less than 0.0001 chips.
Some tables are also needed for these kind of players ( to avoid big walled players ... )
This will make possible to have many new players on the service without Bitcoin involved.
They will be able to play even if they don't know anything about Bitcoin, but it will be enough to get them addicted to the game/service.
Exactly for this reason I keep free roll going on - you do not need a penny to participate in it. It needs just 6 persons to start. And these freerolls restarts every hour or even faster (depending on how popular this free roll is).
So I believe it is best way to try it out - you can play and also you can get some chips you can use to play ring games.