Animated gifs with audio. That's it. Also super easy to create from a camera phone, no video or gif editing skills needed.

I know at least some content producers on youtube will be happy. A lot of vine hate comes from them when random anonymous vine user uploads a tiny portion of their long video and gets tons of views and maybe some ad revenue (or at least takes away potential ad revenue from the youtuber). It's resulted in youtubers creating short clips by themselves on their channel or sister channels, but I can see the annoyance, if not fully understand the complaint since it's no different from the timeless complaint about media being easier and cheaper to distribute and consume than to create.