Tourism has become a popular global leisure activity. In 2010, there were over 940 million international tourist arrivals, with a growth of 6.6% as compared to 2009. International tourism receipts grew to US$919 billion (euro 693 billion) in 2010, corresponding to an increase in real terms of 4.7%[2]. As a result of the late-2000s recession, international travel demand suffered a strong slowdown beginning in June 2008, with growth in international tourism arrivals worldwide falling to 2% during the boreal summer months.[3] This negative trend intensified during 2009, exacerbated in some countries due to the outbreak of the H1N1 influenza virus, resulting in a worldwide decline of 4% in 2009 to 880 million international tourists arrivals, and an estimated 6% decline in international tourism receipts.[4]