From streetwalkers who charge as little as $US5 ($A5.60) per sex act to pimps who bring in tens of thousands a week, prostitution is big business in the United States a study has found.
With a plethora of massage parlours, makeshift brothels, secretive high-end escorts and overt online ads, the underground commercial sex economy has long been known to be complex and extremely lucrative.
The Urban Institute is the first research group to come up with a solid estimate on how much money changes hands and how the market for sex works in eight US cities.
In the tourism and convention hub of Atlanta, Georgia, the underground sex economy was pegged at $US290 million ($A324.00 million) a year - more than the illicit sale of drugs and guns combined.
Sex was also big business in Miami - once again outdoing drugs and guns - although the study sponsored by the US Justice Department found that it had fallen to $US235 million in 2007 from $US302 million in 2003.
The sex trade also shrank in the nation's capital, and at $US103 million a year was in line with drug trafficking and well below the $US160 million spent on illegal guns in Washington.
The most fascinating part of the study came from interviews with pimps, prostitutes and police who provided an intimate, inside-look at the sex trade.
Of the dozens of pimps who were interviewed in jail, many spoke openly of their preference for young white women - or even girls - because they're "easier to manage," better able to blend in and are believed to be what clients typically want.
"They have a saying in the pimp game, 'if it ain't white, it ain't right," one pimp said.
The pimps often imposed daily quotas ranging from $US400 to $US1,000 and would often keep every dollar earned as a means of control, paying the prostitutes in food, housing, clothing and gifts.
They also, unsurprisingly, imposed strict rules.
Many prohibited prostitutes from using hard drugs because it made them unmanageable. Some said they wouldn't allow them to "date black dudes" or young men for fear they would get robbed, beaten or recruited by another pimp.
They typically ran relatively small operations of two to 36 people and sometimes employed drivers, bodyguards, and even nannies.
They said they took home anywhere from $US5,000 to $US33,000 a week, but detailed hefty expenses like hotel rooms, advertisement, and clothing, housing food or even tampons for their "girls."
The internet has helped many sex workers avoid the dangers of the street, although many said they still end up on the "stroll."
