How does information spread? How do you encourage its spread?
These are fundamental business questions. If you introduce a new product or service, how will customer word-of-mouth travel? And they are questions of equal importance for policymakers and nongovernmental organizations. How do you get entrepreneurs in small villages of developing countries involved with microfinance? Or how do you best spread HIV awareness among homeless youth?
Convention and intuition point to one solution: Find people who hold the most influence, typically those who sit at the center of a social network — the hub in a wheel — and “seed” them with the new information. From there, the idea will efficiently reach new ears through word-of-mouth.
Unfortunately, finding these hubs can be a lengthy and expensive process. Picking the five best seeds in a 200-person network requires checking 2.5 billion variations. Consider, then, a network of 1,000 people, or 1 million people.