Methods, systems, and apparatus, including computer programs encoded on a computer-readable storage medium, for tracking activities following a view of a sponsored video content item. A method includes: determining that a user has been presented a sponsored video content item; tracking specific activities after the presentation including identifying activities of the user in a channel associated with the sponsored video content item in a specified time period and attributing the specific activities to the presentation of the sponsored video content item; and surfacing the specific activities to a sponsor of the sponsored video content item.