Judging by all the press coverage, Facebook represents the advertising Holy Grail -- but most marketers still have no idea if it's any good for, like, advertising. At least that's according to eMarketer, which recently published the results of a survey of chief marketing officers about their use of social media. Overall less than half of the 175 execs surveyed by Bazaarvoice and The CMO Club on eMarketer's behalf even knew what kind of ROI Facebook was delivering -- and of these, the majority rated it just "average."

Well, I guess it was inevitable. With millions of bored people whiling away the empty hours on Facebook, reconnecting with old friends and stalking their ex's, there was going to be some hanky panky -- and some relationships were going to be ruined, and some marriages were going to end in divorce. And then someone was going to start a Facebook page (or actually, a bunch of pages) about it.

The online economy, for all its chaotic variety, still seems to produce dominant -- or even monopolistic -- companies, which take the lion's share of revenues in their markets. In 2009 Google raked in $23.7 billion, or 79% of a total search market of just over $30.1 billion. Now a similar dynamic is emerging in the burgeoning world of social media.

The Egyptian revolution has inspired a flurry of debate, even though everyone basically agrees on the fundamental points. If I may summarize the consensus that emerged from people angrily, heatedly agreeing: Social media played a role, but obviously it didn't make the revolution. Human beings did that. Duh.

Venture capitalists have been pouring money into social media startups, and they show no signs of stopping: this week brought news that Path, a new social network which focuses on real relationships, has raised $8.65 million from investors including Kleiner Perkins Caufield & Byers and Index Ventures. As part of the deal, Kleiner and Index are both taking seats on Path's board of directors. Back in November Path raised $2.5 million from backers including Index, First Round Capital, and Founders Fund.

Lest anyone take offense, I should clarify at the outset that I don't view the revolution in Egypt as simply a media case study -- it is obviously an event of earthshaking importance, for Egypt, the Middle East and the whole world. But it also perfectly encapsulates a number of media trends -- and I'd like to focus on those, if I may, without trivializing the broader event.

One year in, the Pepsi Refresh Project encapsulates both the potential of social media and some of its paradoxes: specifically, is there any way to be sure, going into a social media campaign, that it will actually help sell your product? By all accounts, Pepsi Refresh has been a big success in its stated goals of raising Pepsi's brand awareness and burnishing the brand's image, but sales are off nearly 9%.

America's fastest-growing companies are significantly more likely to use social media than their larger, established peers, according to a two studies by the UMass Dartmouth's Center for Marketing Research. The UMass Dartmouth center conducted longitudinal surveys of the Inc. 500, which lists the fastest-growing companies in the U.S., and the Fortune 500, listing the largest companies, to determine how many have adopted different types of social media. According to the UMass Dartmouth comparisons, 71% of the fast-growing companies on the Inc. 500 list said they have Facebook pages, while 59% use Twitter, 50% maintain a corporate blog, and 33% use …

It's one thing to write a lengthy think piece in the New Yorker explaining why social media will never play a significant role in "real" social activism (contradicting conventional wisdom in intriguing, highly marketable fashion). It's another thing to be self-evidently, embarrassingly wrong in this assertion. But to be actually proven wrong in spectacular fashion by historic events which no one can ignore, occurring just a few months later -- well that's just funny.

From a certain perspective, the development of modern society has for the most part simply been the gradual extension of technologies for monitoring individuals through channels including civil bureaucracy, the courts, public education, credit histories, and actual electronic surveillance by security cameras and the like. But this Orwellian process will only be complete when individuals assume responsibility for spying on themselves -- and we may have finally reached that glorious day thanks to social media.