MARUKO DRINKING TEAM Simple, but great. Letting your display sleep is not the same thing as activating a screensaver, because the latter can (if you choose) lock your Mac and make it immediately unusable to anybody who does not have a password.
Additionally, if you use Screen Sharing to access a Mac remotely, the built-in screen savers can eat up all your bandwidth when they kick in (especially if you are abroad accessing a Mac back home) and stall your remote connection. This can make it very hard and frustrating to perform even simple GUI tasks remotely.
So, yeah, if all you want is a black screen, then you don't really need this. but if you need a very simple, low-bandwidth screen saver, this is a great little thing.
(Version 1.0)