Although firms are recognizing the business benefits of Web 2.0 technologies, there is little research examining their use in the organizational context. Drawing on the Innovation Diffusion theory and Technological-Organizational-Environmental framework, we present and empirically test a theoretical model of factors associated with adoption of Web 2.0 technologies in business. We find that the organization’s ‘perceived usefulness’ and importance to open standards are positively associated with the degree of adoption of Web 2.0 technologies while ‘perceived challenges’ is negatively associated with adoption. Further, large firms have a higher degree of adoption. Finally, firms in highly knowledge-intensive and innovation-intensive industries have a higher degree of adoption. Our results suggest that in addition to perceived benefits and challenges, open standards, firm size and industry characteristics play pivotal roles in Web 2.0 adoption. This study can help researchers and practitioners understand what motivates firms to adopt such technology platforms.