I had a lot of fun writing this, and it's great to see it taking off. Waiting 2 minutes was impossible for me, I had to set the counter to 2 seconds while testing it! :)
Yup, and especially how it correlates against Referrer.
Though the author would probably need to add <START> button, to minimize the unintentional fails. Also failing could be adjusted for accidental mouse movements, perhaps by ignoring distances of just couple of pixels.