Free play for an hour is a great idea, and would probably be an excellent thing to do before a tournament, or offer some kind of return discount if it's at a barcade or whatever (one good one I've seen is a stamped card offering half off a beer on a different day). Maintaining a social media account (or two or three - besides Facebook, Twitter and Instagram are good options) is also vital and any machine in the wild should have your social media accounts on it.