Digital platforms are reorganising markets, restructuring the labour force, and redefining the scope of competition. These new intermediaries are transforming economic value creation, industrial structures, and innovative activity, all of which are about to undergo their biggest changes in the post-war era. Platforms have power over their ecosystem members, as algorithms mould users’ incentives to elicit particular responses. This raises the question of whether non-platform firms will be overpowered by the likes of Amazon and Google that have considerable advantages, such as massive data centres and the ability to cross-feed online traffic. The answer is conditional, but its existence puts pressure on the state to adopt an aggressive regulatory role. At this time, we do not have a framework for properly regulating platform businesses. This special issue examines how ecosystems created by platforms reorganise markets and how value creation and capture by incumbents and entrants is affected.