From the website:

Dabble's mission is to help you find and collect videos from all over the web, no matter where they are hosted.
With all of [the] different sources for online video, we knew people would need one place where they could collect videos from all over the web. Dabble gathers video data from hundreds of hosting sites, as well as from tens of thousands of other websites. Dabble keeps a record of where web videos are located, descriptions about the video, who made it, what it's about, how popular it is, and so on.