1. A method comprising: receiving, by a social networking computer system, an advertisement request from an advertiser to advertise using a social networking system; identifying an indication in the advertisement request of an action on an object, the action selectable by the advertiser from a plurality of actions on objects provided to the advertiser by the social networking computer system; identifying an indication in the advertisement request for providing a message to a viewing user that another user connected to the viewing user in the social networking system has performed the indicated action; determining, by the social networking computer system, that the identified action was taken on the object by another user connected to the viewing user; receiving, at the social networking computer system from a client device of the viewing user, a request for social networking information to be displayed in a web page that is within a domain of an external system that is different from a domain of the social networking system; selecting, by the social networking computer system, a story for the viewing user for display on the client device as a social advertisement, wherein: the story is sponsored by an advertiser and is based on the advertisement request received by the social networking computer system, and the story comprises information about the identified action taken on the object by the other user; and sending, by the social networking computer system, the social advertisement to the client device for displaying in the web page of the external system.
7. The method of claim 1 , further comprising generating a plurality of stories for the viewing user, each story comprising information about an action on an object taken by another user of the social networking system who has a connection to the viewing user, wherein the story selected for display is selected from the plurality of stories.