Use of Silk Road, the online drug marketplace, in the United Kingdom, Australia and the United States.

AIMS To investigate the prevalence of awareness of the online illicit drug marketplace Silk Road (SR), consumption of drugs purchased from SR and reasons for use and non-use of SR. DESIGN AND SETTING Global Drug Survey: purposive sample collected in late 2012. PARTICIPANTS The base sample (n = 9470) reported recent drug purchase and resided in the United Kingdom (n = 4315, median age 24, 76% male), Australia (n = 2761, median age 32, 76% male) or the United States (n = 2394, median age 21, 80% male). MEASUREMENTS Online questionnaire. FINDINGS A total of 65% of US, 53% of Australian and 40% of UK respondents had heard of SR; 18% of US, 10% of UK and 7% of Australian respondents had consumed drugs purchased through SR. Across the three countries, 3,4-methylenedioxy-N-methylamphetamine (MDMA) was the most commonly purchased drug (53-60%), followed by cannabis (34-51%), lysergic acid diethylamide (LSD) (29-45%) and the 2C family (16%-27%). The most common reasons for purchasing from SR were wider range (75-89%), better quality (72-77%), greater convenience (67-69%) and the use of vendor rating systems (60-65%). The most common reasons for avoiding SR purchase were adequate drug access (63-68%) and fear of being caught (41-53%). Logistic regressions found that, compared with people from the UK, Australians [odds ratio (OR) = 3.37; 95% confidence interval (CI) = 2.29, 4.97) and Americans (OR = 1.46; 95% CI = 1.10, 1.94) were more likely to use SR due to lower prices; and to avoid SR purchase due to fear of being caught (Australia: OR = 1.65; 95% CI = 1.39, 1.96; USA: OR = 1.62; 95% CI = 1.37, 1.92). CONCLUSIONS While reasons for Silk Road use accord with broader online commerce trends (range, quality, convenience, ratings), its appeal to drug purchasers is moderated by country-specific deterrents and market characteristics.