Vending machines worth it?

Are they worth it? Say I can keep it full, Track it, Kept Clean, Makes sure it works, Maybe even different kinds of snacks (advertising).

1. Can you rent to leave one in a high foot traffic area?
2. What does it cost to leave it in a space (im sure you have to pay to occupy space)
3. Can I take one over at a spot if it already is a machine there? Buy rights to that machine? / make deal with land owner?