well, yodle and reachlocal, amongst others, are trying to answer that question
In general, though, it's hard to do well. Problems include the fact that many people don't turn to google first thing for pizza, that google still doesn't do a good job looking up businesses by name, that even with geo-targeting food delivery is hyper local and very competitive, that even yelp and seamlessweb have interesting penetration in only a tiny handful of cities, etc. Frankly, I don't really think the internet is the wave of the future for a lot of restaurants -- I'll find out about them from word of mouth or from walking around my neighborhood. Plus, adwords is expensive, and irrational competitors can drive keyword prices sky high.
The issues you point out are real and no one so far has answered them conveniently. What do you think will be the parameters for success if someone comes up with a local advertising or promotion platform. What will be the driver for local businesses to generate leads or traffic.
In general, though, it's hard to do well. Problems include the fact that many people don't turn to google first thing for pizza, that google still doesn't do a good job looking up businesses by name, that even with geo-targeting food delivery is hyper local and very competitive, that even yelp and seamlessweb have interesting penetration in only a tiny handful of cities, etc. Frankly, I don't really think the internet is the wave of the future for a lot of restaurants -- I'll find out about them from word of mouth or from walking around my neighborhood. Plus, adwords is expensive, and irrational competitors can drive keyword prices sky high.