Problem Statement: Track an anonymous user to persist state (or lock out of a feature after a timer) on a device that has visited a website. This would need to work with cookies disabled, across browsers, including visits in incognito mode and not prevent two different devices sharing an IP from locking each other out.
I have seen this applied in a few scenarios with the most recent being the NBC Olympics with the stream timer. This has so many uses for "free no sign-up trials" while not giving away everything or limiting features in "try before you buy". Any ideas would be appreciated!