Distribution of embedded content items by an online system

A non-transitory computer readable medium storing instructions that, when executed by a processor, cause the processor to:

• receive, during a current time interval, host videos from a plurality of host content providers and a plurality of supplementary videos from a plurality of supplementary content providers, wherein each supplementary video is for presentation in conjunction with a host video;
• determine an allocation of display instances of supplementary videos in conjunction with host videos during the current time interval;
• receive, for a preceding time interval, for each host content provider, a count of display instances of supplementary videos presented in conjunction with host videos for the host content provider;
• for each host content provider of the plurality, determine a content quality score based on a level of user interactions associated with host videos received from the host content provider and a count of display instances of host videos for the host content provider that were presented in conjunction with supplementary videos for the preceding time interval;
• determine a content quality threshold based on the content quality score of each host content provider, the allocation of display instances of supplementary videos in conjunction with host content videos during the current time interval, and the count of display instances of host videos of the host content provider were presented in conjunction with supplementary video for the preceding time interval;
• responsive to determining that the content quality score for a host content provider is above the content quality threshold, present a host video from the host content provider to a user of an online system;
• responsive to receiving an interaction between the user and the presented host video, determine a count of opportunities for presenting supplementary videos in conjunction with the presented host video based on a type of the interaction between the user and the presented host video;
• and
• responsive to selecting a supplementary video for each counted opportunity, embed each supplementary video throughout the presented host video to present the host video in conjunction with the selected supplementary videos to one or more users of the online system.