It's sort of like a meme, except animated. And other than the fact that this is good, clean humor that can entertain anyone looking to procrastinate for hours, it is also an interesting form of mass media re-using mass media. The clips are usually 2-3 seconds of a tv show or popular youtube clip, edited and then paired with a funny phrase. It sounds kind of silly, but believe me, I haven't laughed quite this hard in a while. If you scroll down to the bottom of each post, you can see who has reblogged about the post, and it's a very twitter-like form of sharing. You can view everyone sharing a stupid little video clip with an out-of-text comic, just to brighten someone's day or to poke fun at something sensitive, like eating too much, being embarrassed to work out at the gym, or not understanding what your professor is saying. I think it's a beautiful form of humor, that has no real point except to lighten up any subject, and it's becoming quite the networking trend.
Not convinced? Lighten up your stress a little and check it out for yourself.