In several previous posts I've mentioned the paradox of Olympic tickets being flat "sold-out," yet huge tracts of seats sitting empty. Many people have written in to solve the mystery. This, from Alf Hickey, reflects the consensus view:
Large amounts of empty seats are actually quite common at Chinese concerts or sporting events that claim to be "sold out." The reason for this is that a large amount of tickets are given to the bigwigs who organize the events so they can guanxi them out ["build relationships"] as needed. Since the Olympics had so many different organizing bodies, the central government, the local Beijing government and the Chinese Olympic committee, I'm sure there were vast amounts tickets given to various officials.
The reason that these tickets are not used is that by the rules of Chinese guanxi, you don't refuse a gift, especially not from someone connected enough to get Olympic tickets. So the tickets to the rowing finals are probably in the hands of people who have no desire to see the event, but just needed to stay in the good graces of some random Beijing bureaucrat. I suspect that the tickets have already changed hands more than once, passed along like a box of moon cakes that no one actually wants to eat.