You can buy just about everything else via the Internet (clothes, electronics, even cars). So why not food as well? Many high-end food producers and gourmet shops have been doing it for several years.
This article from the NY Times mentions a top-notch bakery and a butcher of restaurant-quality meats who are now shipping their food products to consumers. Both of them, the Sugar Bun Bake Shop and DeBragga, sound interesting.