A notification machine may receive an update to a user profile that describes a user and indicates a group of users as being socially connected to the user by a social network. The update may reference a community (e.g., an employer or a club) of the user. The user profile may be modified by including a reference to the community within the user profile. The notification machine may identify a further user who is included in the community (e.g., employed by the employer, or part of the club). The further user may be socially unconnected to the user by the social network. The notification machine may then generate and provide a notification that the further user is employed by the employer. This notification may contain suggestions that the user initiate communication with the further user, become socially connected with the further user, or both.