The interesting marketing angle, in my view, is using YouTube to offer a sneak peak of their product: "See our app, hear our voice."
Just as blogging can lower the boundary between the outside and the inside of a company ("Hi! Here's how we write and think; listen in or comment back if you're interested"), video can do the same thing, even more powerfully. ("Hi! Here's what our product looks like, how it works, and what our folks look and sound like; take a look.")
B2B or B2C, brands and businesses are about relationships, and relationships are built on human voices.