Some might be quick to answer this question with "Because disk space is cheap," which is true. But making disk space highly available, fault tolerant, and secure can be expensive. To meet our availability, fault-tolerance, and security requirements, we have adopted the latest in Internet technology: Cloud Computing. In a nutshell, our disk space is not provided by a single server sitting in one place on the Internet. It exists across multiple servers in multiple locations, by resources shared by other applications. Security procedures ensure the data is kept private and not shared with other applications using the cloud. For more on Cloud Computing, check out the Wikipedia entry.