Gatekeepers are large digital platforms providing any of a pre-defined set of digital services (‘core platform services’), such as online search engines, app stores, and messenger services. These companies have:
- a strong economic position, significant impact on the internal market and are active in multiple EU countries;
- a strong intermediation position, meaning that they link a large user base to a large number of businesses;
- an entrenched and durable position in the market, meaning that their position has been stable over time.
The only reason steam evaded the label is that they're too small and the EU has bigger fish to fry atm.