The development of the Internet as a communication medium has become a double-edged sword for pharmaceutical companies. While the Web has created unparalleled opportunities for companies to develop valuable long-term and close relationships with physicians, it has also meant that physicians now have a much wider choice of sources for gathering information. This brief examines the barriers that companies must address to attract physicians to websites and retain them on a long-term basis, ensuring the balance between meeting the information needs of physicians and increasing the return on Internet marketing investment is maintained.