[ldd-]

Part of it also is that Giphy has licensing agreements with media rights owners to create gifs based on their content . . . they're not just indexing existing gifs.

https://www.wired.com/2016/05/giphy-wants-all-the-gifs/

[mrieck]

They also have deals with twitter/Facebook so if you use a GIPHY URL it's embedded in the post. All other gif hosts get a static image.