I am a lawyer and a poker player. ;)
The NH model is nice precisely because you have fixed locations and events, any time a player wants a game they know where to go.
The breakdown of the "take" is also stable and written into the law: A certain percentage is set as the maximum that can be returned to the players in any tournament (this may seem odd till you realize that it prevents charities from competing with each other over payback rates), I believe that maximum in NH is 80%, but it can be any number. For non-tournament poker a rake is taken. In other games the house wins its normal percentage.
Of the money that is not paid back to the players by way of being put in the prize pool or otherwise won, the charity must receive a certain percentage, and the state takes a percentage. The charities in NH must get "no less than 35 percent of the gross revenues from any game of chance minus any prizes paid" and the state gets 10%. The other 65% of the take goes to the game operators to pay expenses and make a profit.
If you seek it out, you will find the charities in NH LOVE this system (so do the operators) as they get a steady stream of revenue for no cost and very little effort (they are required to do some accounting and have a representative there when the games take place). The players generally think its OK and certainly better than nothing.
Charities are limited to, I think, 10 game nights per year. But because we have the permanent sites and operators, new charities trying to get in their 10 nights a year have almost a year long wait list to be beneficiaries!
Next best thing to outright legal poker, IMHO.
Skallagrim