This is an excellent article asking pertinent questions about.
The general assumption is that hosting a World Cup has to be good for a country: it provides an increase in tourism, creates thousands of jobs and pumps billions of dollars into the country via ticket sales and sponsorship.
But the reality is that this is simply not true. The money spent on hosting the tournament, both the direct cost of setting up the infrastructure (stadiums and security for example) and the opportunity costs (money spend on hosting the tournament that could be used to boost the economy elsewhere) cancel out the revenue. In short, host nations who do an efficient job will be lucky to break even or make a small profit while inefficient or developing nations, such as South Africa, are likely to lose out.
What makes these figures even more astonishing is the fact that FIFA make a lot of money for putting on the World Cup. Indeed, figures from South Africa 2010 show that FIFA gave the insufficient figure of $482 million to assist with their hosting and left the tournament with a $1.9 billion profit
Many people have asked similar questions regarding the value of hosting the Olympics. There is even a facebook page stating why the olympics should not be hosted in the US.