Then even when they are shown the old thread exists, they STILL continue talking about it in the new thread. Now you have 3 threads, with the 2 older threads pushed further away. Rinse repeat.
Edit: Another suggestion is to move the resellers/importers threads out to WTS/marketplace. They're just open offers to sell and not really custom hardware.
I'll PM you a list of reseller threads I think are inappropriately placed at the moment, when I'm home.