Nonprofit Social Network Gains Traction

Facebook and Twitter might get all the fanfare, but a nonprofit in Eagan, Minn., has quietly built a social network that logged 43 million visitors last year.

CaringBridge lets people set up personal sites they can use to update friends and family members during a health crisis. The network got its start in 1997 when a close friend of the founder, Sona Mehring, had a premature baby and asked Ms. Mehring to let people know what was happening.

The organization