Haters gonna HATEOAS (Hypertext As The Engine Of Application State)

The reason nobody does HATEOAS in APIs is because the libraries used by clients don't encourage or even enable it. Chicken and egg.

Why should you care? The real potential is that you don't need a separate API site, you just add links to your existing HTML representations, and optionally provide JSON representations for bots so they don't have to download puny human HTML.

There's a rare of example of this in action in the wild: Canonical's Launchpad. Paper: http://www.crummy.com/writing/speaking/2010-WS-REST/Develope...