For example, to start a game server on your computer so that others can connect to it.
A significant amount of high-speed servers located all over the world.
Full access to PSN
and Xbox Live from your game console.
Guaranteed absence from blacklists anywhere due to someone else's fault. Enter a captcha on sites less often.
Email clients, internet calls, and any other programs that work over the internet.
Allows you to protect all your devices at no extra cost.