John Hagel III, John Seely Brown, and Land Davison: The Power of Pull, 2010:

We need serendipitous encounters with people because of the importance of the ideas that these people carry with them and the connections they have. People carry tacit knowledge. … As edges arise every more quickly, all of us must not only find the people who carry this new knowledge but get to know them well enough (and provide them with sufficient reciprocal value) that they're comfortable trying to share it with us. This helps to explain a contemporary pattern taking place in new areas of human endeavor: Conferences spring up to accommodate the desire of participants to share stories about their experiences with like-minded people.