InformationWeek’s Fritz Nelson ponders the question, and discusses it with me in a podcast.

Nelson also points to a memorable video clip that I somehow missed, in which Stephen Colbert clears up the confusion about the proper perfect-tense form of the verb “to twitter”:

This may well be my most multimediatastic post ever.

Tim wrote a book. The title of Tim’s book is The Twitter Book. Tim didn’t use a pen to write his book. Tim didn’t even use a word processor to write his book. Tim used PowerPoint to write his book. Tim wrote his book very fast, as fast, he says, as he writes “a new talk.” There are pictures in Tim’s book. Pictures, Tim says, “are a memorable, entertaining way to tell a story.” Tim says he is “reinventing the book in the age of the web.” Tim’s book was a lot easier to write than an old-fashioned book would have been. “All I needed to do,” Tim says, “was to write down some notes equivalent to what I’d be saying if I were giving this as a talk.” Sometimes, says Tim, old-fashioned authors “lose track of their plot details.” That didn’t happen to Tim. It’s “much easier,” he says, “to work on things in standalone units.” Tim’s book is a lot easier to read, too. “Most books still use the old model of a sustained narrative as their organizational principle,” Tim says. Tim’s book uses “a modular structure.” Following “a sustained narrative” is hard. With Tim’s book, each page “can be read alone (or at most in a group of two or three).” Tim says that “modularity isn’t the only thing that publishers can learn from new media.” The web, he says, “provides countless lessons about how books need to change when they move online.” I like the web. I’m glad that books are going to be more like the web. I’m glad that Tim wrote a book.

The biggest crowd on the web today is the one streaming through Twitter’s entryway. The second biggest crowd on the web today is the one streaming through Twitter’s exit.

Twitter’s recent growth has been explosive, even by web standards. The number of Twitter users doubled last month, reaching an estimated 14 million. This month, with Ashton’s Million Follower March and Oprah’s First Tweet, the Twitter flock has almost certainly swelled even more quickly. Everybody who’s anybody is giving Twitter a whirl.

But a whirl does not a relationship make. According to a study out today from Nielsen, at least three out of every five people who sign up for a Twitter account bail within a few weeks:

Currently, more than 60 percent of Twitter users fail to return the following month, or in other words, Twitter’s audience retention rate, or the percentage of a given month’s users who come back the following month, is currently about 40 percent. For most of the past 12 months, pre-Oprah, Twitter has languished below 30 percent retention.

Even Oprah, it seems, may already be losing interest. Of the 20 tweets she’s issued since joining Twitter 11 days ago, half came on her first day. She’s made nary a tweet in the last four days.

The half-life of a microblog, it turns out, is even briefer than the half-life of a blog.

When MySpace and Facebook were at the stage that Twitter is at today, their retention rates were, according to Nielsen, twice as high – and they’ve now stabilized at nearly 70 percent. Twitter’s high rate of churn will, if it continues, hamstring the service’s growth, says Nielsen’s David Martin: “A retention rate of 40 percent will limit a site’s growth to about a 10 percent reach figure … There simply aren’t enough new users to make up for defecting ones after a certain point. [Twitter] will not be able to sustain its meteoric rise without establishing a higher level of user loyalty.”

The FT’s David Gelles says that Twitter’s weak retention numbers “give good reason to think that Facebook, with its 200m users and robust retention rates, has little to fear from the flurry of interest in Twitter.” That remains to be seen. Even a modest boost in Twitter’s retention rate would improve its long-term prospects significantly. But if Nielsen’s numbers are accurate, and if they don’t improve, Twitter may turn out to be the CB radio of Web 2.0.

The syllabus. I’m particularly looking forward to Week Two.

Tim Bray, the software writer and self-professed “sicko deranged audiophile,” is getting rid of his jewel cases. He’s been ripping his large collection of CDs into digital files and tweaking his hifi setup to play music off hard drives rather than disks. “I can’t wait to shovel the disks into boxes or binders or whatever, and regain a few square feet of wall,” he says. I’m with him there. The CD jewel case is the single worst technology ever invented by man. It defines, in a truly Platonic sense, the term “piece of crap.”

Now, Bray is looking forward to the fast-approaching day when he’ll also be able to get rid of his many books, leaving his walls even emptier. Their contents, too, will be digitized, turned into files that can be displayed on a handy e-book reader like Amazon’s Kindle. He writes: “I’ve long felt a conscious glow when surrounded by book-lined walls; for many years my vision of ideal peace included them, along with a comfy chair and music in the air. But as I age I’ve started to feel increasingly crowded by possessions in general and media artifacts in particular.” Physical books, he says, “are toast,” and that’s “a good thing.”

He has a sense that removing the “clutter” of his books, along with his other media artifacts, will turn his home into a secular version of a “monastic cell”: “I dream of a mostly-empty room, brilliantly lit, the outside visible from inside. The chief furnishings would be a few well-loved faces and voices because it’s about people not things.” He is quick to add, though, that it will be a monastic cell outfitted with the latest data-processing technologies. Networked computers will “bring the universe of words and sounds and pictures to hand on demand. But not get dusty or pile up in corners.”

It’s a nice dream, and a common one: the shucking off of material possessions to achieve a purer, spiritually richer life. But there’s a deep, perhaps even tragic, flaw in Bray’s thinking, at least when it comes to those books. He’s assuming that a book remains a book when its words are transferred from printed pages to a screen. But it doesn’t. A change in form is always, as well, a change in content. That is unavoidable, as history tells us over and over again. One reads an electronic book differently than one reads a printed book – just as one reads a printed book differently than one reads a scribal book and one reads a scribal book differently than one reads a scroll and one reads a scroll differently than one reads a clay tablet.

The author Steven Johnson, in an essay in the Wall Street Journal yesterday, praises many of the new features of digital e-book readers, but he’s under no illusion that books will make the transition from page to screen unchanged. We’re going to lose something along the way. That became clear to him the moment he began using his new Kindle:

I knew then that the book’s migration to the digital realm would not be a simple matter of trading ink for pixels, but would likely change the way we read, write and sell books in profound ways … Because they have been largely walled off from the world of hypertext, print books have remained a kind of game preserve for the endangered species of linear, deep-focus reading. Online, you can click happily from blog post to email thread to online New Yorker article – sampling, commenting and forwarding as you go. But when you sit down with an old-fashioned book in your hand, the medium works naturally against such distractions; it compels you to follow the thread, to stay engaged with a single narrative or argument. [As reading shifts to networked devices,] I fear that one of the great joys of book reading – the total immersion in another world, or in the world of the author’s ideas – will be compromised. We all may read books the way we increasingly read magazines and newspapers: a little bit here, a little bit there.

Whatever its charms, the online world is a world of clutter. It’s designed to be a world of clutter – of distractions and interruptions, of attention doled out by the thimbleful, of little loosely connected bits whirling in and out of consciousness. The irony in Bray’s vision of a bookless monastic cell is that it was the printed book itself that brought the ethic of the monastery – the ethic of deep attentiveness, of contemplativeness, of singlemindedness – to the general public. When the printed book began arriving in people’s homes in the late fifteenth century, it brought with it, as Elizabeth Eisenstein describes in her magisterial history The Printing Press as an Agent of Change, “the same silence, solitude, and contemplative attitudes associated formerly with pure spiritual devotion.”

When Tim Bray throws out his books, he may well have a neater, less dusty home. But he will not have reduced the clutter in his life, at least not in the life of his mind. He will have simply exchanged the physical clutter of books for the mental clutter of the web. He may discover, when he’s carried that last armload of books to the dumpster, that he’s emptied more than his walls.

In an analysis released today, and covered by Forbes and the New York Times, the consulting firm McKinsey & Company provides a useful, if flawed, counterweight to some of the more excited hype about cloud computing. While granting that “clouds are very cost-effective” for small and medium-sized companies, McKinsey argues that a large company would spend considerably more today if it were to shut down its data center and run all its applications out of a utility-computing cloud. According to its estimates, based on a “disguised client example,” the total cost per CPU per month using Amazon’s EC2 cloud system would run $366, more than double the current in-house cost of $150:

[image from McKinsey presentation; click for larger view]

McKinsey, of course, has an interest in encouraging companies to maintain large and complex in-house IT operations. Consulting firms have, over the years, made oodles of money from “systems integration,” “business-IT alignment,” “data center optimization,” and other services that feed off the vast complexity and expense of corporate IT. And, it has to be said, the numbers McKinsey presents seem a bit skewed, probably understating some of the savings or other benefits of moving to a cloud. For instance, again drawing on a “disguised client example,” McKinsey suggests that replacing an in-house data center with cloud services would reduce IT labor costs by only about 10 to 15 percent:

[image from McKinsey presentation; click for larger view]

I look forward to further analyses of these numbers. I’d be particularly interested in hearing Amazon’s perspective on McKinsey’s comparisons.

Nevertheless, the McKinsey analysis is a valuable one, not least because it underscores how early we are in the development of the utility-computing grid – and why we shouldn’t expect large companies to begin shutting down their data centers any time soon. Then again, I don’t know of any large company that is even considering such a move today or any reasonable analyst that would suggest it. The scenario McKinsey analyzes – the wholesale replacement of a large enterprise computing operation with rented space within an external cloud – is a bot of a straw man. The real opportunity that the cloud offers large companies today is as a supplement or complement to their in-house operations rather than as a complete replacement. The cloud model offers a way to gain access to additional computing and storage capacity, particularly to cover fluctuations in demand or carry out a short-term data-crunching exercise, without having to make capital investments in new equipment or hire more workers. The cloud also, of course, provides a way to tap into powerful software-as-a-service applications that can provide substantial savings, not only in equipment and labor but in licensing and maintenance fees, over the cost of installing an in-house application. (The McKinsey analysis ignores those opportunities.)

Like any utility system, cloud computing becomes more attractive as cloud providers gain scale and experience and are able to push down their prices while improving their services. As each year passes, the economic advantages of an expanding utility system become real for another set of companies. But that process takes time. Don’t expect to see the biggest companies closing down their data centers in the next few years. Besides, the cloud in the end will be more interesting for the new models of computing it opens up rather than for its ability to accommodate the old ones.

UPDATE: Here is the full McKinsey report.

Evgeny Morozov, in blog posts for Foreign Policy, has helped spread the word about how anti-government protesters in Moldova last week used Twitter and Facebook to help coordinate their efforts. In his first post, titled Moldova’s Twitter Revolution, he reported:

If you asked me about the prospects of a Twitter-driven revolution in a low-tech country like Moldova a week ago, my answer would probably be a qualified “no”. Today, however, I am no longer as certain … Technology is playing an important role in facilitating [the current] protests, [with] huge mobilization eforts both on Twitter and Facebook … All in all, while it’s probably too early to tell whether Moldova’s Twitter revolution will be successful, it would certainly be wrong to disregard the role that Twitter and other social media have played in mobilizing (and, even more so, reporting on) the protests.

In a follow-up yesterday, after the protests had fizzled, he wrote:

Let me say this upfront: I don’t think that Moldova’s Twitter revolution failed because of Twitter. No, it failed because of politics – and Moldovan politics are not the easiest kind of politics to make sense of. I firmly believe that social media did a great job; political leadership from Moldova’s opposition simply wasn’t there to exploit it in meaningful and smart ways …

In the case of Moldova, it’s possible that Twitter has made much bigger impact on the new media environment outside of (rather than inside) the Twittersphere by simply feeding a stream of blogs, social networks, and text messages with content. In my view, people who point to the low number of Twitter users in Moldova as proof of the mythical nature of [“the Twitter revolution”] have conceptual difficulties understanding how networks work; on a good network, you don’t need to have the maximum number of connections to be powerful – you just need to be connected to enough nodes with connections of their own.

No doubt, the Moldovan protests will be used as an example of how the Net and, in particular, its social-networking and personal-broadcasting functions can be used to support popular uprisings and, more generally, the spread of democracy. And rightfully so. But before anyone gets carried away by the idea that the Net is a purely democratizing force, it would be wise to read a longer essay by Morozov, titled Texting Toward Utopia, in the new issue of Boston Review. In this piece, Morozov shows how the Net can serve as a powerful pro-authoritarian or even pro-totalitarian force as well as a pro-democratic one. He argues that our liberal Western biases may be distorting our view of the Net’s effects, by leading us to ignore examples that don’t fit with our desires.

Here’s a brief excerpt about blogging:

Outside of the prosperous and democratic countries of North America and Western Europe, digital natives are as likely to be digital captives as digital renegades, a subject that none of the recent studies [of the Net’s democratizing effects] address in depth. If the notion that the Internet could dampen young people’s aspirations for democracy seems counterintuitive, it is only because our media is still enthralled by the trite narrative of bloggers as a force for positive change. Recent headlines include: “Egypt’s growing blogger community pushes limit of dissent,” “From China to Iran, Web Diarists Are Challenging Censors,” “Cuba’s Blogger Crackdown,” “China’s web censors struggle to muzzle free–spirited bloggers.”

Much of the encouraging reporting may be true, if slightly overblown, but it suffers from several sources of bias. As it turns out, the secular, progressive, and pro–Western bloggers tend to write in English rather than in their native language. Consequently, they are also the ones who speak to Western reporters on a regular basis. Should the media dig a bit deeper, they might find ample material to run articles with headlines like “Iranian bloggers: major challenge to democratic change” and “Saudi Arabia: bloggers hate women’s rights.” The coverage of Egyptian blogging in the Western mainstream media focuses almost exclusively on the struggles of secular writers, with very little mention of the rapidly growing blogging faction within the Muslim Brotherhood. Labeling a Muslim Brotherhood blog as “undemocratic” suggests duplicity.

It’s a paradox worth remembering: Democratic media don’t necessarily support democratic values.

UPDATE: Ethan Zuckerman provides a deep analysis of the Moldovan tweets.