I believe Google Places is another good marketing tool, other than Facebook marketing. Once you listed your business in Google Places, they will send you an email on monthly basis showing about the performance of your business listed on Google Places. The report consist of impressions, keywords use, action taken by your target market. In my opinion.. this is similar to business directory.
Google Places is more on business in a particular location, so you can use Google Place for map purpose at the same time it can be used like a business listing and advertising as well. Moreover, it is free.
From the performance report, you can identify how effective is your listing. You can know how many actions taken as compared to the listing impression. After all, I believe it is another good marketing tool. Put as many information as you can, such as your address, website, email, price, payment tool and others. Then wait for the performance result to see how effective is your listing.