We examined Web 2.0 services that provide different levels of knowledge exploitation and developed a framework for classifying existing service models from a knowledge-creation perspective. More than 1000 Web 2.0 application sites were analyzed and classified. We termed the two types of service platforms: Experience-Socialization and Intelligence-Proliferation. These involved four types of service models that we termed as Exchanger, Aggregator, Collaborator, and Liberator. These models show the diversity of existing Web 2.0 applications and provide a framework for a better understanding of operating patterns and value propositions within the Web 2.0 paradigm.