A secondary content such as an advertisement may be inserted based on users' interests in 360 degree video streaming. Users may have different interests and may watch different areas within a 360 degree video. The information about area(s) of 360 degree scenes that users watch the most may be used to select an ad(s) relevant to their interests. One or more secondary content viewports may be defined within a 360 degree video frame. Secondary content viewport parameter(s) may be tracked. For example, statistics of the user's head orientation for some time leading to tile presentation of the ad(s) may be collected. Secondary content may be determined based on the tracked secondary content viewport parameters).