CONTENT-ITEM RELATIONSHIP MESSAGING SYSTEM

A message can be selectively provided to users of an online content management service based at least in part on a user relationship between the users and a shared content item. Users having the user relationship associated with the message can be shown the message, where users without the user relationship are not shown the message. For example, a message can be configured to be shown upon the first time a content item is opened by a user, but not on subsequent openings of the content item.