If you listed the blockbuster offerings that have redefined the global business land- scape, you’d find that many tie together two distinct groups of users. HMOs, for instance, link patients to health-care providers. Search engines join Web surfers and advertisers.
When successful, these platforms catalyze a virtuous cycle: More demand from one user group spurs more from the other. For example, the more video games developers (one user group) create for the Microsoft X-Box platform, the more players (the other user group) snap up the latest X-Box. Meanwhile, the more players who use X-Box, the more developers willing to pay Microsoft a licens- ing fee to produce new games. And as user bases grow, margins fatten.