But animated GIFs aren't dying. They're metastasizing: People festoon their Tumblrs with them, pass them around in email, and use them as Twitter avatars or signatures on discussion boards.

Because, for the same file size (limited to 3 MB on 4chan), you can have a higher-resolution, longer, higher-frame-rate video with more colors compared to an animated GIF, which is limited to 256 ...