What do marketing scholars need to know about markets? The quote above places markets at the heart of marketing theory. Yet many commentators have lamented the scant attention paid to markets in marketing and argued for the need to better understand this central facet of the subject (Araujo et al., 2008; Vargo, 2007; Venkatesh et al., 2006). We share this view and outline issues and research opportunities against the backdrop of recent contributions proposing a practice approach to markets (Araujo et al., 2010; Kjellberg and Helgesson, 2007; Storbacka and Nenonen, 2011; Vargo and Lusch, 2011). A central tenet in this tradition is the idea that working markets are always in the making; that they are the continuous results of market practices. Paraphrasing Vargo and Lusch (2004): markets are not, they become. In this process of becoming, markets take on multiple forms as a result of practical efforts by many different actors to shape economic exchanges, establish rules for their performance, and represent such exchanges as markets. The observation that economic theories (including marketing) contribute to shape markets by influencing these practical efforts (Callon, 1998) introduces a complication in our study of markets and presents a reflexive challenge for marketers studying the shaping of markets.