"I think these shows have a potential for acute embarrassment... All I would say is keep smiling, whatever happens. I watched it last week and whoever the celebrities were forgot to smile when they lost all their money. That's a big mistake."
Gordon Brown advises Piers Morgan when to smile on Who Wants to be a Millionaire
(from Piers Morgan's Diaries Vol 3, p101, which I am very much enjoying, thank you for asking)