This chapter reviews traditional drug market dynamics. With this context established it explores import substitution of cannabis, the exploitation of vulnerable peoples in European drug markets, online drug sales and new psychoactive substance (NPS) markets. An early stage in many illicit drug distribution chains is the procurement of precursor chemicals. Smuggling across borders can be high- or low-tech, depending on the local environment, volume of drugs being smuggled and traffickers’ resources. Trafficking is conducted by a relatively small number of networks, composed of a relatively small number of individuals, who happen to share a particular ethnicity. Traffickers have long used disposable, often vulnerable, people to smuggle drugs across borders: the riskiest link of the distribution chain. The 2000s witnessed increased use of the internet by a range of drug market actors. Some NPS are attractive to traffickers because their high potency means that small packages can be as profitable as larger ones of traditional drugs.