I am not sure how they come up with these figures. Its seems to me that this is more of a marketing ploy then any real figures. Considering the world's population is 6 billion, ( The times of India reported the no of people watching would be 32.3 billion), 3.23 billion means which means over 50 percent would be interested in watching the French and the Italians slug it out in Berlin In India and China alone this number combined is not going to cross 10-20 percent of the population. Similarly for America it is only likely to be 30 percent. I would put most optimistic figures to be around One billion of people who would want to watch this contest. Finally out of these assuming 50 percent actually get down to watching it live puts the number at 0.5 billion. Mind you not a small number by any means.
I believe the 3.23 billion, in theory, to be the population of countries/regions where these matches would be aired live.