Determining whether a user has seen a content item

A non-transitory computer-readable storage medium storing executable computer program instructions for determining whether a user has seen a content item, the instructions executable to perform steps comprising:

• detecting an area of the content item that has been displayed;
• detecting a length of time that the content item has been displayed;
• determining an aggregate score for the content item based at least in part on the detected area and the detected length of time;
• and
• responsive to the aggregate score exceeding a threshold, determining the content item has been seen by the user.

A system for determining whether a user has seen a content item, the system comprising:

• a processor configured to execute modules;
• and
• a memory storing the modules, the modules comprising:
• an area displayed detection module configured to detect an area of the content item that has been displayed;
• a time displayed detection module configured to detect a length of time that the content item has been displayed;
• and
• a score aggregator configured to determine an aggregate score for the content item based at least in part on the detected area and the detected length of time, wherein responsive to the aggregate score exceeding a threshold, the content item is determined to have been seen by the user.