Clive Thompson at New York Magazine thinks deep thoughts on why a certain Tennesee law professor gets 150,000 hits a day, and the rest of us do not. Much too whiney and superficial, but offers some interesting gossip on background stories, money, ad rates, and who gets what hits.

…if you talk to many of today’s bloggers, they’ll complain that the game seems fixed. They’ve targeted one of the more lucrative niches—gossip or politics or gadgets (or sex, of course)—yet they cannot reach anywhere close to the size of the existing big blogs. It’s as if there were an A-list of a few extremely lucky, well-trafficked blogs—then hordes of people stuck on the B-list or C-list, also-rans who can’t figure out why their audiences stay so comparatively puny no matter how hard they work. “It just seems like it’s a big in-party,” one blogger complained to me. (Indeed, a couple of pranksters last spring started a joke site called Blogebrity and posted actual lists of the blogs they figured were A-, B-, and C-level famous.)

That’s a lot of inequality for a supposedly democratic medium. Not long ago, Clay Shirky, an instructor at New York University, became interested in this phenomenon—and argued that there is a scientific explanation. Shirky specializes in the social dynamics of the Internet, including “network theory”: a mathematical model of how information travels inside groups of loosely connected people, such as users of the Web.

To analyze the disparities in the blogosphere, Shirky took a sample of 433 blogs. Then he counted an interesting metric: the number of links that pointed toward each site (“inbound” links, as they’re called). Why links? Because they are the most important and visible measure of a site’s popularity. Links are the chief way that visitors find new blogs in the first place. Bloggers almost never advertise their sites; they don’t post billboards or run blinking trailers on top of cabs. No, they rely purely on word of mouth. Readers find a link to Gawker or Andrew Sullivan on a friend’s site, and they follow it. A link is, in essence, a vote of confidence that a fan leaves inscribed in cyberspace: Check this site out! It’s cool! What’s more, Internet studies have found that inbound links are an 80 percent—accurate predictor of traffic. The more links point to you, the more readers you have. (Well, almost. But the exceptions tend to prove the rule: Fleshbot, for example. The sex blog has 300,000 page views per day but relatively few inbound links. Not many readers are willing to proclaim their porn habits with links, understandably.)

When Shirky compiled his analysis of links, he saw that the smaller bloggers’ fears were perfectly correct: There is enormous inequity in the system. A very small number of blogs enjoy hundreds and hundreds of inbound links—the A-list, as it were. But almost all others have very few sites pointing to them. When Shirky sorted the 433 blogs from most linked to least linked and lined them up on a chart, the curve began up high, with the lucky few. But then it quickly fell into a steep dive, flattening off into the distance, where the vast majority of ignored blogs reside. The A-list is teensy, the B-list is bigger, and the C-list is simply massive. In the blogosphere, the biggest audiences—and the advertising revenue they bring—go to a small, elite few. Most bloggers toil in total obscurity.

Economists and network scientists have a name for Shirky’s curve: a “power-law distribution.” Power laws are not limited to the Web; in fact, they’re common to many social systems. If you chart the world’s wealth, it forms a power-law curve: A tiny number of rich people possess most of the world’s capital, while almost everyone else has little or none. The employment of movie actors follows the curve, too, because a small group appears in dozens of films while the rest are chronically underemployed. The pattern even emerges in studies of sexual activity in urban areas: A small minority bed-hop, while the rest of us are mostly monogamous.

The power law is dominant because of a quirk of human behavior: When we are asked to decide among a dizzying array of options, we do not act like dispassionate decision-makers, weighing each option on its own merits. Movie producers pick stars who have already been employed by other producers. Investors give money to entrepreneurs who are already loaded with cash. Popularity breeds popularity.

In scientific terms, this pattern is called “homeostasis”—the tendency of networked systems to become self-reinforcing. “It’s the same thing you see in economies—the rich-get-richer problem,” Shirky notes.