You don't want to jump off the wake, you simply want to straighten out your knees, so that your legs are extended, before you leave the wake. I'm not exactly sure what causes the added pop, but it has something to do with sinking the board, and the boat pulling you forward through the wake. If you try to actually jump off the wake you'll end up squirly, without any height. You got to remember that you're moving at 20+ mph. When you try to jump, you stop all your momentum, by pushing straight down. It's almost like jumping out of a car at 20+ mph, and trying to land without falling down... Something like that, but different.
I know that's not the best description, but maybe it'll help. Anyone got any more advice?