* The "sign-in before you'll let people follow" is just a straight forward result of A/B testing. It was like a 9-to-1 difference for single site returns. And despite the developer in me saying "gross", it was just a stat from our metrics guy that we couldn't refute.
* We're in Minnesota and Amazon's been playing games with our affiliate revenue to encourage some legislative changes... But even if the affiliate revenue was working perfect, it wouldn't be enough to keep the lights on. TrackIf is really just a platform to demonstrate our business solution (like how Home Depot does back-in-stock notifications)
* What's a UK based site you want tracked? I could wire it up for you.
* Amazon does all sorts of price games, geography/time-on-site /Prime-status/etc.