Tracer Bullets and AB testing

I recently read about Tracer Bullets as an alternative (or supplement) to Prototyping. While the lines are kindda blurry on some subject, I think I get the big picture.

But it got me thinking...

Are Tracer Bullets what we use, when we do AB-testing? I mean, we make small changes in fully functioning environments to see what sits best with the end-user.

Hope that someone can help clarify any differences, and if this question belongs on another Stack forum (like sqa) please let me know, and I'll move it ASAP.