This article asks the question as to whether existing antitrust tools are suitable for dealing with perceived antitrust concerns raised by online platforms by focusing on three examples: (1) market definition and market shares; (2) barriers to entry; and (3) the role of innovation as a safe harbor or as a defense. It concludes that these concepts should and will continue to play a significant role in the antitrust analysis of online platforms but need to evolve and adapt to the new requirements of the digital economy. Costly mistakes, both in terms of failure to intervene when required and erroneous interventions, may occur if this does not happen at the speed that the pace of economic development requires.
