Drug app comes free, ads included

Epocrates has won over nearly half of the nation's doctors for its free smartphone apps that lets them look up information on drug dosing, interactions and insurance coverage while seeing a patient. But like so much else on the Web, "free" comes with a price: doctors must wade through marketing messages on Epocrates that try to sway their choices of which drugs to prescribe. The apps can select messages based on each doctor's search and prescription histories, and the company has ambitious plans for expanded smartphone offerings. One possibility is a virtual sales rep that would help drug makers get their wares in front of physicians who decline to see human sales representatives.