youtube is a pit of spam in general. Basically any bigger video, every single comment that's even just somewhat high up either has a respond that says something

youtube is a pit of spam in general. Basically any bigger video, every single comment that's even just somewhat high up either has a respond that says something like "check this out <video link>" or "see here <video link>", or a comment left by someone with a username along the lines of "click my profile picture for my pics" with a suggestive avatar