How do organizations develop, buy and sell incremental innovation as a service? In many knowledge-intensive business-to-business settings the locus of interaction has shifted from stable, discrete, and articulated products and services to the exchange of somewhat nebulous capacities of problem-solving, innovation and R&D services. In these exchanges, tensions and conflicts between actors can arise in seeking clarity as to what is being exchanged and how it is valuable, while at the same time attempting to keep the interaction open for future adjustments to the scope and content of the exchange. We combine a longitudinal case study of a chemical services firm with Galison's (1999) concept of a trading zone and contributions in industrial services marketing to assess how actors offer, value and exchange incremental innovation. Focusing on the contentious nature of innovation processes, our contributions to the understanding of intra-and interfirm behavior in marketing and purchasing are threefold:(1) We examine how incremental innovation is formatted as a tradable service; (2) We explain how buyers, sellers and developers exchange the service of incremental innovation even when this service remains contentious in its specification; (3) We argue that trading zones complement relational processes and contractual arrangements by allowing actors to preserve their own logics and expertise pertaining to innovation.