>To eliminate support calls I would simply design a system where any place they went FROM their email would work - maybe up to 3 or 4 links past email.
What? What constitutes a "link"? This doesn't make any sense.
How are you determining this without sniffing everyone's traffic? How do you know if someone typed youtube.com into their browser window or clicked a link from an email without access to things like referral headers?
What? What constitutes a "link"? This doesn't make any sense.