Editors and copywriters working away in the small press biz sometimes have a difficult time understanding the differences between Marketing, Advertising, PR and Branding (as well as their importance). Marty Neumeier's illustrations—taken from his book "ZAG: The #1 Strategy of High-Performance Brands"—provide the best explanation we've seen:

I'm going to help Joost keep their marketing budget small. Seems like an interesting product. I'm not sure why, but viral marketing is all the rage these days-it's like it's viral or something. Anyway, I have Joost invitations, so you should get them while they're hot.
 
It's not that I don't like sitting mindlessly in front of a colorful box frittering my brain away, I just do that on the internet instead. Whether wasting time watching cable television or YouTube and Digg is worse, is an academic debate - actually there is probably a PHd dissertation rolling around in there somewhere.

So Joost is pretty much television over the internet. They have deals with MTV, National Geographic, etc.

I have yet to really get under the hood, but it seems pretty interesting. You get to watch shows when you want to watch them, which is the way television should be. Keep in mind Joost is still very beta, thus the invites only - and occasional glitches.

If you haven't gotten your joost invite yet, post here or link here and I'll make sure you get one.