Sociologists have developed a different approach to understanding social movements that draws from our understanding of both collective action and organizations. Resource-mobilization theory recognizes that social movements need to generate adequate, and often substantial, resources to achieve their goals  The resources they need to muster are extensive. They include money, membership, office facilities and equipment, communication processes, political influence, and a skill base with expertise in organization, leadership, and marketing the cause. Successes and limits are set by the resources a movement is able to mobilize.