A political party leader in Thailand and former massage parlor owner stated that the prostitution industry in Thailand is earns over $6.4 Billion (200 Billion Thai Baht) a year in revenue. The amount generated by the sex trade in Thailand is equal to roughly 10 percent of the country’s GDP.
(More prostitution revenue by country.)
Source: “Party leader demands Thai govt take action to stamp out prostitution,” Asia One, February 13, 2012.