Despite the FBI shutting down the Silk Road back in 2013, people’s confidence in the dark web as a marketplace for illegal drugs doesn’t appear to have wavered, with the number of monthly transactions on hidden online markets having trebled in the past three years.

Known as cryptomarkets, dark web marketplaces are only accessible using browsers like The Onion Router (Tor), which scramble traffic through a network of relays around the world in order to anonymize users. According to a new study commissioned by the Dutch government, dark web drug sales now total between $12 million and $21.1 million a month, which is double the monthly revenue seen in 2013.

Despite this growth, cryptomarkets still represent only a fraction of all illegal drug sales, which continue to occur mainly on the street. In Europe alone, the offline drugs market currently has an estimated worth of around $2 billion per month.

Yet the study authors believe there may be a growing link between the online and offline drugs markets. The fact that more than a quarter of all dark web drug sales in January 2016 were of $1,000 or more suggests that street dealers may be buying their stock in bulk online, before selling it on in smaller quantities.

Breaking the data down further, the researchers found that while certain drugs are increasingly being traded on cryptomarkets, others are still very much sold via more traditional routes. Ecstasy, for instance, now accounts for almost a fifth of all dark web sales, compared to just 3 percent of all street purchases.

^{Though dark web drug sales are still massively overshadowed by offline sales, certain drugs - such as ecstasy - are increasingly being sold via cryptomarkets. ShutterDivision/Shutterstock}

Overall, the US has the highest number of dark web drug dealers, making 35.9 percent of all revenue. The next biggest earners are based in the UK, Australia, and Germany. The endeavors of these cryptomarket vendors are also becoming increasingly lucrative, with the highest earner in January 2016 pocketing $276,230 – a 10-fold increase on the most successful dark web dealer in 2013.

The ever-increasing popularity of the Dark Web has come as a surprise to some, as the risks of using cryptomarkets are also spiraling. Not only have a number of these marketplaces – such as Silk Road 2, Agora, and Evolution – been shut down by the authorities, but growing numbers of buyers have also been hit by exit scams, whereby cryptomarket administrators suddenly remove their websites, running off with all the Bitcoins deposited by users.

Though the dark web was never supposed to exist solely for drug dealing, it is becoming increasingly hijacked by narcotics vendors, with 58 percent of all dark web sellers now shifting nothing but drugs.