If we don't need one, why did we buy one? We bought one because we wanted one. Confused? Read the article to find out why we wanted one.

Apple’s iPad is just one year old, and more than 15 million customers have voted with their wallets. The tablet is officially mainstream.

But just what is a tablet good for? It’s not a complete replacement of a PC and it’s not a necessity for anyone who carries around a notebook or a smartphone. At best, it’s a “tweener” device.

If it’s not a necessity, doesn’t do many things as well as a notebook and lacks the portability of a smartphone, what’s the key to its success?