[weavejester]

It provides an additional layer of security over HTTPS/BasicAuth, so if your SSL certificate or even the CA is compromised, you retain a degree of security.

On the other hand, it makes it more difficult for developers to access your API; you can't just send requests over Curl, for instance.

[arethuza]

Good point about curl - a strong motivation of mine was to make the API easy to access through tools like curl.

[I have seen some discussions about adding explicit support for OAuth in curl]