There are hundreds of thousands of English websites advertising mail-order drugs to, primarily, Americans. They are based in the U.S., in Canada, the Caribbean, and all over Europe.

Some of these sites advertise in the little side-boxes on search engines, such as Yahoo and Google, and some send out spam-mail. (You know the ones: Discount Cialis! Cheap Viagra!)

A lot of these sites are run by affiliates: men and women who advertise for a cut of the sales. Their 100,000+ web sites advertising and pricing drugs, re-direct orders to many fewer sites: say 15,000. These are the online pharmacies. The affiliates are like freelance sales-people. They have accounts set up with bigger companies, and they get a cut of each sale they bring in -- sometimes as much as 40%. What that amounts to really depends on how high they set their prices before you stop buying.

The 15,000 or so sites that your drug orders are directed to are the actual commercial engines. Behind each site, there is at least one real person, a credit card processor, a bank account, and an access to a store or buyer's account of pharmaceuticals. This is, in practice, a real company: there's a purchasing department, a sales department, a shipping/receiving department, a sales/marketing manager, IT, etc. A company with 30 people can sell and ship massive quantities of drugs.

Not all online pharmacies are operating illegally. Not all are operating 100 percent legally. A big problem for them, and for law enforcement, is that the rules have been fuzzy for some time. The 2008 Ryan Haight Act that passed through Congress in October 2008 made some of the rules stricter, and clearer.