Abstract: Server side content impression progression tracking is performed using ping triggers and pings. A server generates ping triggers for content based on an impression list from a configuration provided by the content originator. The server sets different times at which the ping triggers are to fire during content playback. When media playback on a client reaches a time set for a ping trigger, the ping trigger causes the client to return a ping to the server to indicate that playback has reached the designated time. In this manner, the pings granularly track content viewership on different clients, wherein the granular tracking measures not only whether content was viewed or not, but also how much of the content was viewed. Subsequent content to a particular client can be customized based on preferences derived from pings tracked from the particular client.