'Business model' is a fairly new academic concept; competing with Porter's 'sustainable strategic competitiveness' and 'strategic fit' (Porter, 1996), Prahalad & Bettis 'dominant logic' (Prahalad & Bettis, 1986) to give key explanatory understanding of firm performance. We discuss business modelling based on an action research case and show just how fundamental it is. It links fundamental academic discussion of recent decades around concepts such as 'sustainable competitive advantage', 'structural capital' and 'tacit knowledge'.