The author of a study of sex trafficking around the United States says metro Atlanta topped the list in part because of the many conventions held in the city.

The report, conducted by Washington D.C.'s Urban Institute for the U.S. Justice Department, looked at the sex trade in eight major American cities and found that Atlanta had the largest sex trade between 2003 and 2007.

"Atlanta went from $232 million to $290 million over that five year span," Meredith Dank, the lead author for the report, told WSB Radio. As a comparison, $290 million is more than the revenue generated by metro Atlanta's illegal drug and gun trade combined.

Atlanta's revenue also was far above any other city studied, with Miami second at $200 million. Denver's sex trade was worth $40 million, San Diego's $97 million and Dallas' $99 million.

The culprit? Dank says the many events and conventions in the Atlanta bring people to town with lots of time and money. Some escorts charge more than $1,000 per hour.

One pimp the researchers spoke with in Atlanta made, on average, about $33,000 a week, according to the WSB story.

According to FBI statistics, Atlanta ranks among the top 14 cities in the United States for domestic minor sex trafficking. And some 300 girls across Atlanta are lured into trafficking every month.

Earlier this month the Junior League of Atlanta presented “Stop the Candy Shop,” a documentary examining domestic minor sex trafficking in the city. About 500 children are trafficked for sex in Georgia every month, according to Street GRACE, whose mission is to stop the exploitation of children