Drug companies have new top salesmen: doctors. According to the Wall Street Journal, hiring a doctor to speak about drug therapies to other doctors has proven to be a "highly effective" way for the pharmaceutical industry to market its drugs. "An internal study done by Merck & Co. several years ago calculated the 'return on investment' from doctor-led discussion groups was almost double the return on meetings led by the company's own sales force," the Journal reports. "According to the document, doctors who attended a lecture by another doctor wrote an additional $623.55 worth of prescriptions for the painkiller Vioxx over a 12-month period compared with doctors who didn't attend. Doctors who participated in the more intimate discussions wrote an additional $717.53 worth of prescriptions for Vioxx, which Merck pulled from the market last year over concerns about cardiovascular side effects. That compared to an increase of only $165.87 in Vioxx prescriptions by doctors who attended a meeting with a salesperson."