WikiWealth

"According to a survey conducted by the United Nations World Tourism Organization (UNWTO) in 2007, Thailand was ranked the 18th most visited country in the world with 13.9 million visitors annually. Tourists come to Thailand for a variety of attractions including tropical islands, world famous beaches, museums, archaeological sites, and festivals, as well as, Thailand's unique cultural heritage. Tourist numbers have grown from 336,000 foreign visitors in 1967 to over 14 million international guests visiting Thailand in 2007. This generated an estimated 547,782 million Thai baht, around 11 billion Euro In 2006."

Source: http://internationalbusiness.wikia.com/wiki/Tourism_in_Thailand_-_MMV