What number of UK users constitutes a 'significant number' for the purposes of the Online Safety Act 2023?

One of the tests as to whether a user-to-user service is a “regulated” service, for the purposes of the Online Safety Act 2023, is whether the service has “links with the United Kingdom” . A service has “links with the United Kingdom” if: the service has a significant number of United Kingdom users, or United Kingdom users form one of the target markets for the service (or the only target market),…