Pharmaceutical companies in industrialized countries generally view detailers as the most crucial element in the promotion of their products, with the result that over 50 percent of expenditures on promotion are devoted to detailers. Publicly the companies make claims for the scientific knowledge of detailers and for their role in passing on information to physicians, but the main purpose of detailers is to sell their company's products. This emphasis on sales is evident from statements of detailers themselves, from advertisements for detailers, from company documents, and by looking at the groups of physicians that companies specially target for visits by detailers. A variety of explanations are offered as to why physicians see detailers, but on examination none of the reasons is justifiable. Studies from a number of industrialized countries have shown that over 90 percent of physicians see detailers and a substantial percentage rely heavily on detailers as sources of information about therapeutics. Detailers are highly successful in altering physicians' prescribing habits, but almost all the literature available shows that the more reliant doctors are on commercial sources of information, the less appropriate they are as prescribers. Widespread use of DES (diethylstilbestrol) and the Dalkon Shield was encouraged by detailers. Although detailers have received the endorsement of both physicians' groups and government bodies, seeing detailers is detrimental to the practice of good medicine, and the best interests of doctors and their patients would be served if physicians had nothing further to do with detailers.