Carl Bialik at the Wall Street Journal, aka, The Numbers Guy, torpedos the nutty claims about a video that a marketing firm estimated had been viewed 900 million times:
But the Viral Factory’s rankings, commissioned to publicize the launch of a U.K. television show composed of popular online clips, were little better than a guess — and a different way of guessing for different videos, to boot. The company generally added up public view numbers from online-video sites such as YouTube and Metacafe, then supplemented those totals with its own estimate of views elsewhere.
You should always take these kinds of estimates as essentially meaningless. They get publicity — which often seems to be the main point — but do not inform anyone of anything especially useful.
The media, including bloggers, are prone to accepting such numbers without doing any homework to see if they’re ridiculous. Only rarely does someone like Bialik look more closely, and the result frequently is a thorough debunking. A lesson there.