We all know that without Twitter, Facebook, Blogs, FourSquare, etc (Social Media) the Gourmet Food Truck industry would have never been born. How would you tell a customer where you are? How would build a following? You wouldn't.
You use twitter notifications Facebook messages not only to communicate your locations and upcoming events but even more importantly build an ARMY of loyal followers that promote your business. They in tern use even more tools to extend your reach. They re-tweet your posts, add reviews on Yelp & Urbanspoon and write clever and informative blogs. You can build on this even more by treating these people as VIPs after all they are giving you free advertising, no even better they are giving friends, family and followers their personal recommendation.
Chef/Owners, now you can use this power by interacting with your customers via social media. When they compliment you thank them. When they write a blog or review tweet it out or add it to your Facebook "Like" page. They will then continue to push your "BRAND" to the public.
You could even offer your strongest supporters discounts, or deals knowing in turn they will bring you new customers and the cycle continues. If your going to be at a special event or location tell them via a Facebook invite. Its the personal touch that keeps them coming. If the planed event/dinner starts at 6:00 PM tell them the time is 5:30 and thats only for them.
You may not see immediate quantifiable results but you will see your followers and customer base grow. More and more people will walk up to your truck feeling like they know you and they are on the A List.