Web 2.0 technologies and social media can be used as a platform for value creation. While some firms are successful in engaging with external audiences on social media, others are less so. Many of these firms have equal access to web 2.0 platforms and operate in similar or same conditions, the resource based view (RBV) offers an explanation for disparities in performance of these organisations: the differences are due to firm internal, valuable, immutable and rare resources. Comparing high- and low-performers in a comparative case study helps to identify and highlight firm internal idiosyncratic resources that result in better sustained performances. In-depth studies inside the organisations answer the questions how and why some firms on the same platform can attract higher engagement levels than others. The problem is how to recognise best and worst performance to conduct in-depth case studies? This paper introduces ALIAS – a methodology for identification of the relative firm performance within a population, and selection of theoretically relevant cases to conduct comparative case studies through the lens of RBV. The proposed methodology is a five step process and utilises the DART framework of value co-creation for identification and assessment of performance criteria