This paper describes the development of a maturity model to assess the Web-2.0-ness of websites. The model draws on O’Reilly’s Web 2.0 principles and patterns. It distin-guishes six dimensions with four degrees of 2.0-ness each. The rating scheme has been evaluated and refined to improve inter-rater reliability in a discussion and a coding iteration. This model raises awareness for 2.0-ness, helps to benchmark website design, and supports decisions about 2.0-ness adoption. Based on aggregated scores and a normal distribution, our sample of 44 pharmaceutical over-the-counter (OTC) product websites is classified in three maturity stages: Innovators, Adopters, and Laggards. The model can also be used for other industries and website types. In five of the six dimen-sions, at least one website reaches the top degree, but n one achieves top grades in every dimension. Diversity in 2.0-ness is observed for product websites in the pharma-ceutical industry, as well as for one company’s different product brands. Further re-search will extend the 2.0-ness analysis to the overall web presence, including social media sites. Another next step is to relate 2.0-patterns to websites’ success measures.