I flew from Frankfurt to IAH on Friday, January 7th. I am silver elite. I asked the GA whether there were extra seats in business class and whether people would be upgraded. He explained that it was Continental's policy not to upgrade people unless economy was overbooked. He was also a completely supercilious prick who told me that I should buy a business class ticket next time. I am unsure whether he worked for continental or lufthansa. While I take him at his word that economy was not overbooked, it looked completely full, while business class was about half empty.

Is it true that op ups only occur when coach is overbooked? I am ignorant on the subject and haven't found a good answer yet.