Toony-BasicOutline Shader on 2D SpriteRenderer?

I'm trying to use the Toony-BasicOutline shader on a Unity 4.3+ SpriteRenderer. I have already followed the advice to make this shader work in an orthographic camera.

The shader works fine for 3d objects, but the SpriteRenderer still doesn't show the outline. I don't know much about writing shaders. Is what i'm doing possible? If not, why and is there another shader that provides this ability for SpriteRenderer?