It's another thing to have a link or entry that does nothing more than promote the business. I removed an external link to a listing of a local chain of restaurants for that reason. From your description, Nunh-huh is doing nothing more than providing free advertising.
If enough people added enough advertisement to Wikipedia it would cease to be advertisements. Because you would only stumbe upon the advertisement if you went looking for restaurants in New Haven, Connecticut, in which case you probably appreciated the info.
--------------------------------------------------- BIG MAC & C:O IS REALLY GOOD ON MCDONALDS!! EAT IT! ---------------------------------------------------
And with that little statement I've probably made an advertisement that is much much more effective than whatever someone who added something to New Haven, Connecticut could ever do unless he had another advertiser who went on to make a really big fuss about it.
BL