Interesting you should bring that up. I was just last week going through the phone book and noticed most of the companies spending big money on ads where service companies. Product companies with store fronts seem to be depending more on location to sell.
The one industry I find that goes outside that mold is Auto Dealers. People will travel far and wide for the best deal so the dealers are willing to spend the money on the ads for a very large target area.
The Home Improvement or Home Repairs (Plumbers, A/C, etc) Industries seem to be the ones catching on the quickest from what I am seeing.
Absolutely true, Chicago. I have several clients (futons, catering, flooring) who are kicking butt in the local arena by taking full advantage of online local search. Two of them, the futon and the catering guys, more or less shifted their entire YP ad budget over to online, with great results. Ortelius