The Youtube Exchange is an idea I came up with. What you do is use the comments of this video as a kind of forum thread. You can post advertisements, promote your channel, trade and share information, or even just talk with other people.
To search for certain things, simply click "see all" next to comments. Then press "Ctrl + F" to find what you want.
I will not delete any comments ever, and voting will not be allowed, to keep everyone's comments equal.