Lifehack gets it. On the virtues of using wiki : Good tool to brainstorm ideas: If you are not familar with tools like FreeMind for mind mapping, wiki may be your best tool.
But the real insight is this : It is all due to the fact that the way that wiki markup able one to edit content easily.
Though, remember everyone, that the virtues of wiki-nature also apply to local wiki-like things, such as, say, SdiDesk. ;-)