To me, the Long tail concept relates only to the online business. If you want to make everything available, as the concept suggests, you needn't to worry about space storage.
Take books for exemple. Thousands upon thousands books exist and aren't hits. It doesn't mean they are bad and shouldn't be read. In fact, it only means they are not available to the public, or very difficult to obtain.
Through the long tail concept, amazon makes these books available - among hits. With recommendations by the readers, the retainers or the critics, these books will make themselves known to the buyers and will sell ! The hits will be a way for amazon to make the other books known.
http://www.amazon.com/Vampire-Lestat-Anne-Rice/dp/B000OVTKVA/ref=sr_1_4?ie=UTF8&s=books&qid=1260463904&sr=1-4See for yourself. At the botom of the webpage linked, there is recommendations or suggestions by amazon for books that are in the same category that the one I am interested in. Some of these books, I knew, some I didn't. Amazon makes them avalaible to me through mail order or through their kindle (which allows me to purchase online electronic books and read them on the device).