United Internet AG

1&1 IONOS, Strato, and Sedo operate separately in web hosting, domain registration, and domain marketplaces. All three sit under one corporate umbrella: United Internet AG, a €5.6 billion German conglomerate that controls one of Europe's most comprehensive domain and hosting ecosystems.

The company was founded in 1988 as 1&1 EDV-Marketing GmbH by Ralph Dommermuth and Wendelin Abresch, operating out of the small German town of Montabaur as a marketing and advertising service provider. It moved into digital services early. It now runs over 27 million customer accounts across more than 30 locations worldwide as a full-stack internet infrastructure company.

The domain numbers are substantial: United Internet brands manage over 5.2 million domains, a 2.02% share of the global domain market. Coverage matters as much as volume. Through united-domains (supporting over 270 TLDs), IONOS, Strato, and the marketplace Sedo, the group touches the domain lifecycle from registration through to resale.

The brands are specialized rather than overlapping. InterNetX handles bulk domain registration for resellers. Sedo handles premium domain sales and purchases. IONOS handles enterprise cloud hosting with domains attached. Strato handles budget-friendly European hosting.

The €600 million Strato acquisition in 2017 bought more than a hosting provider. It completed the European coverage puzzle, adding Strato's strong German market position to complement IONOS's enterprise focus and an existing portfolio of country-specific leaders including home.pl in Poland, Arsys in Spain, and World4You in Austria.

Two divisions run the group: Access (telecommunications including DSL, mobile, and fiber networks) and Applications (domains, hosting, cloud, and email services). That telecommunications backbone, including 1&1 Versatel's 67,000-kilometer fiber network, means a domain registered through a United Internet brand sits on infrastructure the group owns all the way down to the physical fiber carrying the traffic.