The CTI program requires hands-on testing locations around the country, not just in Pendleton, SC where CTEF is headquartered. Furthermore, in addition to the hands-on test itself, the program includes an orientation the evening before the test, not to mention cleanup.
So committing to being a CTI test location host means you're willing to give up a good bit of space for some serious tile installation action over more than a day.
In the case of Tile ProSource in Tennessee, the owners not only generously offered CTEF warehouse space but also treated everyone involved in the CTI test to a tile-themed feast. Plus, they've also added to their online checkout process an option to donate to the CTEF Mission!