PatientsLikeMe (PLM) is an online community where patients share their personal experiences with a disease, find other patients like them, and learn from each other. The company was founded by Jamie and Ben Heywood when their 29-year-old brother was diagnosed with ALS or Lou Gehrig's disease. In...

Social networks, such as Facebook and Myspace have witnessed a rapid growth in their membership. Some of these businesses have tried an advertising-based model with very limited success. However, these businesses have not fully explored the power of their members to influence each other’s...