In my thesis I set out to provide an explanation of how sales and marketing works together to produce business-to-business (B2B) value propositions. My thesis is grounded in the discipline of marketing and draws substantively on Sales and Marketing Interface (SMI) and Value Proposition literature.I deployed a novel research methodology in which an Engaged Scholarship approach was combined with a Critical Realist philosophy and an individual actor focus. Twenty-One B2B sales and marketing practitioners were interviewed and a thematic analysis of interview transcripts was undertaken. Analysis was informed by extant SMI and value proposition literature and outwith literature from fields such as theology and anthropology.I found that value proposition production at the SMI is a much more dynamic process than depicted in extant literature. I found a much more fragmented and tribal view of sales and marketing identity in contrast to the holistic, monolithic entities portrayed in extant literature. Enablers and barriers to SMI value proposition production were found to be 'below the surface' issues related to identity, contextualisation, and actor thought worlds.My thesis provides a unique view of value proposition production at the SMI. I have moved the conversation forward from a functional level dyadic view of SMI interactions to a much more dynamic depiction of how fragmented marketing and sales actors work to produce value propositions.I provide models for depicting non-normative causal mechanisms for SMI value proposition production moving the discussion forward from the normative factors that dominate extant literature.3