"Street" selling is the bottom of the chain and can be accomplished through purchasing from prostitutes, through cloaked retail stores or refuse houses for users in the act located in red-light districts which often also deal in paraphernalia, dealers marketing merriment at night clubs and other events, or directly from dealers who have purposefully engaged adolescents (typically). Many users sell in order to fund their own drug use. Although most are in it for the monetary outcome, some view narcotics dispensing and consumption as a means of insurrection and orchestrate it for that cacoethes. They refrain from intensive processing and abstain from umpteen 'business' practices. Although most dealers market to a changeless customer base, these mavericks may be overly advertised on hacker/phreaker/drug/etc. forums and between friends and cohorts.
U.S. Government guide to spending on illegal drugs (http://www.whitehousedrugpolicy.gov/publications/drugfact/american_users_spend/)
U.S. DOJ history of illegal drug trade (http://www.usdoj.gov/dea/deamuseum/museum_illegaldrugs.html) (rather self-serving and biased, represents DEA as triumphant over drugs)
Dealers of "soft" drugs such as marijuana and psychedelic mushrooms often cite their motivations as the philanthropic desire to facilitate their recreational use, and tend to view drug prohibition laws as immoral restraints of personal civil liberties.
These drugs are associated with the highly visible and chaotic patterns of use, often associated with criminality, that shape the stereotypical media portrayal of the 'junkie' or 'crack head'.
Illegal supply of these so called hard drugs is driven mainly by the economics of drug prohibition, with huge profit margins available due to the collision of high demand for the drugs with harsh laws that attempt to prohibit their supply and use.
Mexican drugtraffickers are the primary transporters of the major narcotics imported into the US The 2,000 mile shared border between Mexico and the US is the entry point for a large percentage of these drugs.
Additionally, he indicated that Mexican drug organizations have established methamphetamine laboratories that have been estimated to produce 85 percent of the methamphetamine available in the US Overall, Mexican drugtraffickers have become a significant supply source for most of the major drugs consumed in the United States.
Mexican drug organizations, the DEA report continues, have established labs throughout Mexico and California, in addition to super-labs that are able to produce hundreds of pounds of methamphetamine in a week.