Flexible.
You can work out your payment plan. Say you get paid next Friday, but you want to put a dollar on a game on Sunday, you can with credit. Problem is, nice guys in credit get taken advantage of, so the bookie has to be firm with the conditions. But as a credit player, you should always be good on your word. As a credit bookie, you should start small and probably work with someone who is established to carry the red figure until you are on top.
The moral of the story is integrity. If you fuck around with someone, you are most likely going to get burned yourself.