"As seen on" surfaces videos popular elsewhere on the Web, and now it also lives on the video page. In other words, if a blog or site is responsible for driving a significant amount of a video's views, that site will be credited on the page, as so:
What this means is that you can get recognition for sourcing videos that your readers love and helping those clips become popular on YouTube. It's another way all that hard work you put into building your readership can pay off and generate even more traffic for your blog or site. You might even get your site in front of a whole new audience via people who encounter it for the first time on YouTube.
We're currently experimenting with this functionality on a range of popular videos and plan on making it a permanent feature soon.