Confused about do not disturb on iPhone 5?

I keep seeing commercials and such for this feature on the iPhone 5 and I don't understand what's so great about it or why it's needed. Isn't putting the phone on do not disturb the same thing as just switching it to silent mode? What is the point?

Yes it is. Its just a way to pull dumb apple leeching customers to buy it. Apple sucks an are complete ripoffs

Have you ever upgrade your iPhone to iOS 6? Yes? Then 'Do Not Disturb' feature is available for your iPhone!
It is right inside the settings menu on iOS 6. If you do not want anyone to disturb you by your phone when you are sleeping on your bed sweetly, try it!
It enables you to the Notifications that do not receive phone calls at a certain time or receive calls from certain people. Well, of cource, if a person calls you more than once within 3 minutes, you will know that. IPhone is smarter, right?

Do Not Disturb suppresses all notifications (calls, texts, emails, etc.) while your iPhone's screen is locked; your iPhone will not light up, vibrate, ring, or alert you while DND is on and the screen is locked. Any suppressed notifications will be logged and waiting for you when you unlock your screen (start using it again).

Do Not Disturb also allows you to set one exception group to receive calls from while active, so that all other notifications will be suppressed, but this group's calls will ring through (though texts will still be suppressed).

While in silent mode, your iPhone will still light up and alert you, which can be annoying if you're trying to get some sleep. Do Not Disturb keeps your iPhone from bothering you and sends calls straight to voicemail, unlike silent mode.