In the past two years on YouTube, videos with "review" in the title had more than 50,000 years' worth of watch time on mobile alone. Appears In Make the grade for back-to-school: 4 YouTube trends to inform your video strategy Related Data Black millennials' mobile watch time on YouTube has more than doubled in the last two years. In the past two years, videos with the word "review" in the title had more than 50,000 years worth of watch time on mobile alone. Black millennials watch substantially more YouTube on mobile than other millennials. There has been a 65% YOY increase in watch time for the top travel-related YouTube videos on mobile devices. Mobile watch time of test drive videos on YouTube has grown by over 70% in the past two years. Views of travel-related videos increased 41% in August and September 2018 compared to 2017.