This is taken from the Why Linode Page:

Virtualization is the future of hosting. It eliminates the restrictions of shared web hosting, and the expense and upkeep of dedicated servers. And, it’s kinder to the environment by more efficiently utilizing resources.
Better than shared web hosting

Shared web hosts are notorious for overselling their servers — packing as many sites as they can onto their machines, which translates into poor performance. Shared hosting is restrictive – you’re at the mercy of the provider. A Linode’s resources are guaranteed. You have total control over your Linode to install custom software and run the versions of services you need.
Better than dedicated servers

Dedicated servers are expensive to rent or purchase and maintain, and often you’re the one worrying about failed equipment. They’re overpowered and underutilized. Out of band access and remote rebooting capabilities cost extra. With Linode, you share in the cost of the hardware with others, have complete root access, and have tools available that only virtualization can provide — like instant OS reinstalls, recovery modes, remote console and reboot capabilities, and much more…

I just found it a very interesting explanation of why to consider virtualized or cloud computing over tradition dedicated and shared hosting approaches.  I think IT professionals will keep arguing this on into the next decade, but I really think cloud computing is here to stay.