What is Completion rate?
Completion rate is the share of the audience that consumed the content to the end: saw the last slide of the carousel, watched the whole video, reached the last story in the sequence. It is retention summarized in a single number. A high rate shows the hook promised what the content delivered and that the call to action, which sits at the end, was seen. Long carousels with a low rate usually have too many slides or a middle slide that does not move forward; story sequences lose people with every tap.