ok. this is an about number, but there are 56 million who watch it each year, which is 20% of our population. no wonder its the most popular sport in america!
Just to get some figures, in the 2006 world cup 2.2 billion people watched it. So in 2010 it could reach 3 billion. Mind you it is the most popular sport in the world.
Well i know that in the united states we have to fill out forms they are called censis and you send them back and they scan them and then they can tell how many people are in the USA but i don't know...