Cocaine is an extremely addictive drug. Intriguingly, under the umbrella of NPS, recreational users can find not only newly synthetized substances, but also old” compounds sold as supplements and weight-loss drugs or typically used in clinical setting, two of which have been investigated by Andrea Petróczi and her collaborators of the Kingston University (UK).
Our findings show that illicit drugs like cocaine are just another commodity and that as with any competitive market place, a retailer drugs without prescription with something to sell will look to maximise the purchase experience in order to gain a competitive edge over other suppliers.

This seems very similar to EMCDDA estimates about drugs sold offline, apart from ecstasy-type drugs (just three per cent of the total European retail drug market) and heroin (28 per cent of the total European drug market, but just six per cent of the total drugs sold on cryptomarkets).
But the dealers who had been selling the drugs on the market migrated to competing sites set up with a similar infrastructure, using the Tor web browser, which hides the location of the websites and their viewers, and Bitcoin, which allows for essentially anonymous payments.

Cryptomarkets are online venues for the purchase of drugs (and other contraband) protected by technology allowing for anonymous communication (e.g., Tor software, Seattle, WA) and using currency designed to be difficult to trace (i.e., cryptocurrencies such as Bitcoin).
Richard Downing, who oversees the computer crime section of the Justice Department, said he and his colleagues have focused on techniques that create distrust on the sites by encouraging users to believe that sellers and site administrators have already been compromised and are feeding information to law enforcement.
I hadn't ever thought about selling drugs in any capacity because I dislike violence and it just seemed impossible to be involved in selling drugs in real life” without running into some sort of confrontation pretty quickly… I was always too scared and slightly nerdy to do that and never really contemplated it seriously until the dark web.

The operators of dark net marketplaces are intelligent, cunning, and very adept at dodging law enforcement, playinga long game of cat-and-mouse that they don't mind occasionally losing because they know there will always be a demand forthe products they peddle and that business can be conducted over smartphones, which 68 percent of Americans have.