This chapter offers an analysis of joining a so-called vertical marketing department at Virtual World as an apprentice marketer. What does it take, and what does it mean, to become a competent member of a marketing department? How are the practices of vertical marketing made sense of in the organisation? From an ethnomethodological perspective, marketing practice is constituted in and through accounts produced and exchanged in the cultures employing the language of marketing. As in Chapter 1, if markets can be understood as ‘sets of accountability’ (Dilley, 1992a), this chapter further asks what kinds of sets of accountability vertical marketing performs. How are vertical markets and marketers held accountable through contingent exchanges and assessment routines? How is their agency constructed? Becoming a member of a marketing department means, in the fi rst instance, learning the ways of accounting for marketing as everyday practice.