I have just started to understand the world of SEO, but what I gather and from just thinking abut it, if you are an online company where your customers don't really care/know about your location, chances are registering with Google's Local Business Center will not make a difference. With the deli example, every day internet users would search for "deli in NYC" (or some location) and that is why a certain deli in NYC would want to register with Google. But if your customer base isn't searching for you based on your location, then I can't really see the benefits of registering. But I don't see any harm with it either.
That is my two cents :o)