From Knowledge Jolt:
[B]logs can be used to extend the socialization framework that we get when smart people gather around the cube, board table or in the lunchroom. In those situations, people are sharing and learning from one another, but it happens only within a small group of people who happen to be near each other. With blogs (and admittedly other social software) people can extend that reach out to larger and larger groups of people…. Humans seem naturally inclined to share and help one another, and the capabilities being developed with blogging give people more opportunities to do so.