Creating audience segments for campaigns is described. In one or more embodiments, an audience manager is configured to create, for one or more videos, a video audience segment associated with the video by storing, in a data management platform, user identifiers of users that viewed the video. The user identifiers can be received from a client player each time that a video is played at the client player. The audience manager is further configured to extract demographic information from a demographic report associated with the video that is received from a demographics provider, and to associate the demographic information with the video audience segment. The audience manager is further configured to generate a target audience segment for a campaign by merging and combining user identifiers that are included in two or more video audience segments.