This is a great idea; I've seen these boards up at some (few) eateries in PGH. I just wish the 1 outta 10 free food abusers would go away. I'm kind of impressed with all the places that keep water out for the dog walkers. (The water is for the dogs only. Ask me how I know!)
I've given boxes of dog treats to quite a few places down in Lawrenceville (section of Pittsburgh) as I think if someone lets their dog meet people and a business is nice enough to keep fresh water outside their business, they should get a gimme also.
Lots of daytime dog walkers down there. They like my Angel Dog, too. She's a real "people" magnet! Especially when the girl also has a Weim. But, as long as the dogs are happy, I can only use my imagination! And forward some treats for other dogs.