It seems odd that a seller of illegal drugs hiding on the Dark Net might be concerned about reputation, but new research suggests that besmirching character is the best way to go about shutting down the dangerous trade.

Scientists at Ohio State University took a long, deep dive into the murky world of online opioid dealers and found that trust between drug seller and drug buyer was the single most important factor in the black market business.

Sociologists Scott Duxbury and Dana Haynie spent six months monitoring traffic on a large Dark Net drug market – a trading hub accessible via the anonymising software known as Tor.

They discovered that the marketplace operated in much the same fashion as ebay or Etsy, with buyers advertising their wares, and both sides of every transaction providing evaluations that aggregate into a reputation score.

In a paper published in the Journal of Quantitative Criminology, Duxbury and Haynie report that for Dark Net drug buyers, the price of the goods was not an important factor in deciding when and from whom to purchase.

"When opioid users are making that first purchase, price doesn't matter at all," said Duxbury. "If they come back to buy again, price matters a little, but trust remains their primary concern."

The study included 57 sellers and 706 buyers. The pair noted that most of the customers bought drugs only once, for reasons that weren't clear. Among repeat buyers, however, most did not shop around, but instead stuck to a single vendor.

The research identified three sellers who dominated the market. Rather than mount operations to forcibly shut them down – as happened with Silk Road and AlphaBay – the sociologists suggest attacking their reputation, destroying the trust bond between them and their customers.

Doing so, they noted, would dramatically dilute the illegal opioid marketplace, leaving most buyers – whether new or experienced – without the ability to purchase.