The mathematical term for it is "luck"
Portfolio.com blogger Felix Salmon normally spends his time dryly bemoaning how much smarter than me he is. But buried at the end of a lengthy piece of guesswork decrying the not-as-smart-as-Felix-ness of Valleywag's new pay scale, the guy does some actual reporting:
One thing I've noticed in my years blogging is that your most popular posts are never your best posts, and that it's pretty much impossible to predict which posts are going to catch on and get lots of pageviews. The new Gawker pay scheme, then, might well end up simply rewarding the lucky, rather than the good.
Exactly, Felix, exactly! By the way, Felix, here's a trick I use to mask my lower IQ: Take your conclusion and move it from the last sentence to the first, as I've done to you here. It allows people not as sharp-witted as Felix Salmon to understand why they should bother reading the rest of your article.