Sports are a huge business. For example, the world's most famous sport is soccer. So, when the world cup comes around, there is a lot of business going on. The host country gets a huge benefit in terms of the economy as the world comes to visit. Tourism, the service industry, and many other areas of the economy can be seen to pick up. Airlines, as you can imagine, also benefit. Then there is all the money that comes from advertisement, endorsements, and the like. In short, international sports can be very lucrative for many.