Exemplary embodiments relate to techniques for notifying existing users when a new user joins a messaging service (or returns from a period of inactivity). A top n number of existing users acquainted with the new user may be selected and may be encouraged to message the new user. The existing users may be selected using a messaging coefficient that indicates a likelihood that a message will result in a meaningful conversation, and a number of other factors that prevent the existing users from becoming inundated with notifications. The number n may be selected based on an amount of display space available to the new user in a messaging application. When inviting the existing users to contact the new user, a new thread may be automatically created and bumped to the top of the new user's thread list.