Its whatever you decide. But older stuff is usually 50/50. If your going to be putting in top dollar stuff(Think $4k+) then you should be getting 60/40. I think self redemption/bulk vending stuff is like 65/35.
I have heard some people will pay to buy/steal the location from another operator. But I think those days are long gone. Not enough money to be made to fight for locations..
about the only thing that operates well is drivers, shooters(and then you deal with broken guns), and neo geo. If your going to run neo, you want a 4 slot. You need to put in a bust a move (any of the series), metal slug (any of the series), and whatever else you want. Probably a flying game (aero fighters or strikers), and then maybe something like super sidekicks, samurai showdown, ect.