At the heart of the frenzy are some familiar names: the likes of Alphabet, Amazon, Apple, Facebook and Microsoft. A similar, though less transparent, battle is under way in China among firms like Alibaba and Baidu. Several have put AI at the centre of their strategies. All are enthusiastic acquirers of AI firms, often in order to snap up the people they employ. They see AI as a way to improve their existing services, from cloud computing to logistics, and to push into new areas, from autonomous cars to augmented reality (see article). Many observers fear that, by cementing and extending the power of a handful of giants, AI will hurt competition. That will depend on three open questions, involving one magic ingredient.