The bottom line is that you need to be everywhere someone might search for you whether your business is local, national or international. In the old days, there was only one place to find listings — the phone book. Now there are thousands.
The bottom line is that your competitors are on Google Page One and on the Google Places Map. Unless you are ranked above them for your search terms, you are missing out on a lot of potential opportunities. This is also true on Bing, Yahoo, Merchant Circle, Insider Pages, Yellow Pages Online, etc.
If your business is national, it still comes being found and that includes content and several other factors while always staying within the acceptable Google guidelines.