You aren't the Chamber or Visitor Center. Give them their phone number or website and tell them to ask them. Just say I only have stuff in the house for guests and don't do marketing for the area :-(Loss leader or long tail. Essentially getting the info out there where guests can find it.
Good point about what to give away and what to charge for. Some guests want us to send them all kinds of info BEFORE they will book. Hmm, that's what the tourist info phone number is for. I'll happily send you a carton of stuff after you book. (Yes, I tell them to look online at the enormous amount of info I have compiled, but they want 'stuff' in the mail.).