Amazon.com Comes to Health Care

Electronic commerce couldn't be hotter these days and health care start-ups are trying their hands at "e-tailing." Venture firms have backed Drugstore.com, PlanetRx Inc., Chemdex Inc., MotherNature.com and Greentree Nutrition. However, the companies are working from new, evolving business models, and it isn't yet clear how they will make money--whether the majority of profits will come from taking a distributors' cut on product sales, from Web-based advertising or some other service integrated into online shops.