I'm not entirely sure that I understand how the Custom Channels work, or if there are "best practices" for them. The documentation is pretty vague on them.

What I do know is that I had created one channel for my site and added all of my ad units to it, then gave a description for my site. That seemed to be generating a lot of revenue, so later I created a separate channel for each ad unit, and in the description described both the site and the ad placement and value. This generated more revenue. It's confusing, though, because now I have each ad unit linked to two channels; I'm afraid to remove the original one because I don't want to lose advertisers that are targeting it.

So the question I have is, how, exactly, does the Description work? Should it be loaded with keywords for advertisers to find, or is it just a description they'll read after they've already found it?