how to deal with a persistent facebook user messaging you frequently?

[Brandon]

Well, obviously as you can see, you are going to run into this problem with Facebook. Facebook was created with the everyday-user in mind- not the everyday business owner. And so they didn't initally intend for business owners to use it as a marketing tool. If you want to give it a rest. I suggest making a "Page" (which users can "Like") rather than using your personal Facebook page to market your business. You're not "cry wolf[ing]" you're just stuck, and I totally understand it. If he is really bothering you, then tell him straightforward that you are here solely professionally and that he can find many of his answers through Google, as you say. Just act with a professional manner and you will be able to get him off your ass. I would suggest maybe ignoring him and just keeping a separate Facebook page for your private use.

Hope that helped.