How's That Again?

There's a commercial they run every few seconds on MSNBC for an online backup storage service called Mozy. In it, a lady says the following…

For only $4.95 a month, you get unlimited storage. That's enough space to back up your entire computer.

Uh, isn't "unlimited storage" enough space to back up every computer in the world a trillion times? I mean, it's unlimited, right?