Between September and November of 2011, volunteers with End Slavery Tennessee emulated research methodology provided by Operation Broken Silence by tracking online ads on the Nashville section of Backpage.com, a Web site that is similar to Craigslist, but features an adult section.
During the course of the three month assessment window, the study found that 2,051 unique ads advertised sex for sale in the Nashville area.
"They need to be shut down completely," said Kathy Hines, a former VICE officer with the Detroit Police Department and a volunteer with End Slavery Tennessee.
The study found that the average cost of sex that is purchased through the Web site in Nashville is $154 if in-call and $216 if out-call.
The average age of the women was 25, but researchers suspect it is actually younger.
"I believe [the ages are] much, much lower," Belmont University student and researcher Lindsy Anton said, adding, "From what we saw in some of the ads, we saw the pictures I think we saw a lot of minors in those."
According to the study, 41% of the area codes represented Tennessee area codes, while the remaining 59% were dispersed throughout 38 states.
"That's a huge trafficking indicator," she said, adding, "That means they're crossing state lines, so that it's a federal crime."
Anton and Hines told Nashville's News 2 they are always looking for signs that the individual pictured in the ad is being forced into prostitution against his or her will.
"Sometimes we'll catch distressed looks, not looking at the camera, sometimes they won't show their faces," said Anton.
Both said they can never be entirely sure if someone is a willing prostitute or a victim of human trafficking.
"When you're told you better make this look good or I'm going to beat you or kill your family, your mindset totally changes," said Hines.
Nashville's News 2 attempted to contact backpack.com for a comment, but they have yet to respond to the request.