Mick Foley had a good analogy in his second book, Foley is Good, about writing his first book, Have a Nice Day! A small book is like a tiny white, uh, "toy." It might not be special, but it's less intimidating and sells better. A massive book is like a baby's arm holding an apple. It catches your eye at first, but no one it willing to "try it out."
A ten minute video is like a lil white "toy," an hour long video is a baby's arm holding an apple.
However, when you don't have a store on the street corner and you're hoping on word of mouth to lead people to your vendor's cart under a bridge beside the sex addict's convention, the baby's arm holding an apple might be your best seller instead.