This chapter develops a neo-Aristotelian account of commercial ethics, treating market relationships as commutative interactions guided by mutual benefit, proportionality, freewill, and goodwill. It clarifies just commercial exchanges—from product features and truthful information to fair pricing and client suitability—and frames markets as communities ordered to the common good. It argues that fairness requires proportional gains and attention to consumer sustainability (i.e.: consent alone is insufficient) and outlines criteria—common benefit, proportionality, just price as benchmark, degrees of cooperation, and double-effect for collateral impacts. It links these principles to shared value and the value chain: better products and access, circular productivity, and local clusters that strengthen cooperation. It also contrasts responsible conduct with recurring abuses, including predatory lending, price discrimination akin to usury, pyramid and Ponzi schemes, misrepresentation, and other deceptive bad practices in commerce. Conceiving markets as social communities and exchanges as matters of commutative justice, it offers a practical framework that integrates profitability with human flourishing and the common good. It underscores the social nature of exchange, where benevolence toward counterparties strengthens sustainable, long-term relationships and responsible pricing and disclosure.