Persistent URL query string throughout the entire site?

Question

This is one of those situations where I feel like there is a simple answer right in front of me...hopefully you guys/gals can show me the light.

PROBLEM :

Answer 1

If you just want to persist this exact query string on each page, why not set the linked pages to insert the string into a session variable. Then on each page link check to see if the session variable exists and add it to the query string when redirecting.