Maybe less is sometimes more. Facebook serving 1B/month while Youtube serves 1.2B/day.

But, last I heard, Google is yet to make money off Youtube. Facebook may be finding that video can be an value-adding supplement to its business, not just a bandwidth-sucking enticement to the lowest-common-denominator of the masses. [ "not that there's anything wrong with the latter" - it just doesn't seem to make for a profit center, even for Google.]