“YouTube tends to recommend progressively longer and more popular content to users. This analysis illustrates how YouTube’s recommendation engine encourages users to engage with progressively longer content. The videos encountered in the first step of these random walks (that is, the initial starting videos chosen at random) collectively averaged 9 minutes and 31 seconds in length. But the first videos selected by the recommendation engine were nearly three minutes longer on average. Average video length then progressively increased for each subsequent recommendation. By the fifth and final step in these walks, these videos were on average nearly 15 minutes long”.