I wonder whether this is due to the fact that the YouTube kids app (on iOS and Android at least) doesn't have any limit on the number of videos that will autoplay without any form of engagement from the user. My son has several times now left RyansWorld et al videos playing, we've left the house and gone out, and come back 4 or 5 hours later to content still happily streaming away to no-one. Great for Ryan, great for YouTube, not so great for the advertisers paying for these phantom views. I'm fairly sure that the non-kids version of YouTube will timeout if there's no user engagement for X number of autoplays.