Google semi recently bought You Tube and has been spending the entire time trying to figure out how to make money off of the website. Unfortunately a website with that kind of traffic that streams video is going to use millions of terabytes of bandwidth and thus is going to cost a damn fortune.
More recently, Google has started adding video to its search results allowing people to use video to usurp other competitors with clever, most often watched videos. A fantastic example of a company doing this is Blendtec. If you haven't seen a Blendtec blender commercial, youre in for a treat. Hockey sticks, marbles, cell phones, magnets... nothing is a match for this 220v powered blender that needs to be bolted to a counter to keep it from literally flying away.
Google apparently saw the Blendtec videos too, because now you can promote videos on YouTube's main page and *for a nominal fee* your video can be put on the main page in a pay per click fashion. Effectively turning YouTube into a pay per click driven advertising source - similar to television. Its a brilliant idea that allows a much more effective conveyance of ideas and product than 25 characters across the top of a SERP. Kudos Google and Youtube on being brilliant, yet again.