Unlike many other products and services, online healthcare can be not only a substitute but also a complement to offline healthcare. For minor illnesses, online and offline healthcare are substitutes. However, for major illnesses, earlier online diagnosis may facilitate earlier offline treatment, and in this sense, they are complements. We develop a theoretical model that incorporates this distinguished feature of online healthcare and study the impact of improved online technology on the quality choice of the general practitioners (GP). We show that, in contrast to conventional wisdom, the improved online technology may cause the GP to lower his service quality.