This is, to me, a really strange statistic. Print is more important than YouTube for Content Marketing. I realise I have a Business-to-Business bias but I really don't consume much of anything through print, either as a consumer or for work.
Clearly I'm missing a trick somewhere or a lot of marketers are still churning out Print because that's what they've always done. Maybe if product specs are considered to be content then brochures and so on would count but still; bigger than YouTube? Wow.