Thanks for clarifying. I'm still a bit confused and since I've thought of doing this same thing at a potential startup I'd love to know the details.

So you searched for lake listings on other sites, contacted the lister and offered to add them into your system? What kind of response rate did you get for that? I'd imagine you wouldn't hear back from most of them?

How about adding them by default and then contacting them and saying "I've add your listing to our site so you can have an idea of how it works. If you choose not to join, let me know and I'll delete it."