Most of the premium spots have already been taken up, and if you're forced to franchise or lease one, then you'll come across clauses that means you can't place your unit within X distance of another Bitcoin atm.
As for how much you'll earn, you should try contacting other Bitcoin ATM providers and ask how much they earn. Then you'll need to estimate whether you're likely to get the same numbers where you end up placing your unit.
Thank you, that's one reason I want to go it alone, so I am not hampered by the
franchise agreement. I know one other BTC owner and they're doing at least 2 BTC a day, but am not certain how many machines his has