“the more frequently an individual uploads content the less likely it is that it will reach a success threshold.” That much is clear from their data. What is rather less clear is why this happens. After all, uploaders clearly get better at producing videos as they persist, presumable because their video editing and uploading skills improve. And in fact video producers receive higher ratings for their later videos, even as their success rate declines. Wu and Huberman suggest a reason: “when a producer submits several videos over time, their novelty and hence their appeal to a wide audience tends to decrease.”
— technologyreview.com, study of YouTube video uploads and “success”.