Click data alone is a weak signal - partial consumption data is significantly more informative. Tracking what fraction of content a user actually consumed - the percentage of a video watched, the portion of an article read, the segment of a song played - gives the system a direct measure of satisfaction rather than intent alone. A click followed by immediate exit carries very different meaning from a click followed by full consumption. Sending engagement depth signals allows the recommender to distinguish genuine interest from accidental or disappointed clicks.