15 year-old Ollie (Oliver6596), who spoke with me from his home in Birmingham, UK, admits that he doesn't usually spend much time planning his vlogs, and maybe that's what I find entertaining about them - I don't think he knows any better than his audience where each vlog is going to end up, or when he'll throw himself into a random door. His little brother is his sidekick / antagonist, but you'll never take the brotherly name-calling seriously.
Ollie's vlogs are already working for him - he offered a few in his college (referring roughly to the UK equivalent of high school in the US) application - and was well received (more in the interview).
Ollie's definition of vlogging is one of my favorites (or, in this case, favourites):
Vlogging is...being social awkward to a camera.