Don't put chewing gum on the chair

Trident chewing gum are running a promotion to win tickets to see Beyonce at the O2. To publicise this they left folding chairs around London with a gold envelope marked 'Open Me'. If you read the instructions inside you were told to take that chair to Westfield that afternoon for a giant game of musical chairs, the top prize being a private box for 15 people at the Beyonce gig. It was really funny watching people's reactions to the chairs, from oblivious disregard to nervous intrigue. The snag we discovered was that often people would open the envelope, read the instructions, but not take the chair - so a new envelope would have to be added after they'd gone.
The musical chair game was entertaining, as 300 people scrambled, all desperate not to lose. At one point as the chairs became scarce there was a funny but potentially dangerous pile-up of bodies. But kudos to the chap who gave up his seat to a lady, when it looked like she was going to be 'out' - he was justly rewarded for his gallantry with a Beyonce ticket anyway.