Research outfit Pear Analytics randomly sampled 2,000 tweets from the public timeline over a two-week period and categorized them as News, Spam, Self Promotion, Conversational, Pass-Along Value and Pointless Babble (click on image to enlarge).

Unsurprisingly, the largest portion, 40.55 percent, fell under Pointless Babble, which Pear Analytics loosely defines as those “I am eating a sandwich now” tweets. Conversational ranked second with 37.55 percent, and Pass-Along Value a distant third with 8.7 percent of the tweets captured. Oddly, Self Promotion and Spam ranked fairly low, with 5.85 percent and 3.75 percent of total tweets captured, respectively. Still, both were higher than News, which ranked at the very bottom, with 3.6 percent.

“We thought that both Spam and Self Promotion percentages would be much higher,” Pear noted in its study. “Also, we thought the News category would have more weight than dead last, since this seems to be contrary to Twitter’s new position of being the premier source of news and events.”

Fifty million new users in under four months: Impressive.

“For us, growing to 250 million users isn’t just an impressive number; it is a mark of how many personal connections all of you have made, and how far we at Facebook have to go to extend the power of connection to the billions of people around the world,” CEO Mark Zuckerberg wrote in a post to the company blog.

If Facebook is able to maintain its growth, it will easily hit 300 million users before the end of the year, perhaps as early as November. And as a recent study from Nielsen Online found, users are spending increasingly more time on the site. Americans spent an average of four hours, 39 minutes and 33 seconds on the site in June–significantly more than any other Web site.

Clearly, Facebook is a lot more than “the flavor of the month,” as News Corp. (NWS) chairman and owner of rival MySpace (and this site) Rupert Murdoch once called it. But how long before it’s able to turn its popularity into profit befitting its user base?

Not much of a surprise here, I suppose, given the level of anticipation that typically accompanies the release of a new iPhone. Nielsen says “anticipatory buzz” for the iPhone 3GS was near-deafening. “The new iPhone 3G S sent blog mentions up 1,226 percent week-over-week on June 8, the day of the announcement. After the initial announcement, buzz dipped but again picked up after the phone became available to consumers on June 19, with blog mentions more than doubling compared to the week prior.” The chart, below (click to enlarge):

Brand new MySpace CEO Owen Van Natta started things off Monday with his first day on the job. He was joined by new COO and former AOL exec Mike Jones and new chief product officer and former Sling Media exec Jason Hirschhorn. Down in Los Angeles at the AlwaysOn OnHollywood conference, Boomtown ran smack into Huff Post mastermind Arianna Huffington, who extolled the virtues and abilities of new managing editor Jai Singh, former editor-in-chief of CNET Networks. At AOL, in preparation for spinning off the Time Warner (TWX) Online unit, new CEO Tim Armstrong began appointing new senior execs and spinning off existing ones. Platform-A president and former Yahoo (YHOO) sales exec Greg Coleman, who joined the AOL team in February, is leaving the company, to be replaced by Jeff Levick, who is leaving Google (GOOG)–where he had a close relationship with Armstrong. CFO Nisha Kumar is also leaving AOL, and a search is underway for her replacement. MediaMemo has more on Time Warner’s decision to spin off AOL. A number of Flickr engineers were laid off Wednesday, but Chief Architect Cal Henderson has left the company of his own accord and is working on a stealth start-up with Flickr co-founder Stewart Butterfield. Last, but not least, one of the voices covering the digital scene has found a new gig. Owen Thomas, self-described “scourge of [Silicon] Valley,” is leaving Valleywag to head up GE (GE) unit NBC Universal’s new “Bay Area” Web site, whose motto is “Locals Only.” He’ll be replaced by fresh-faced Ryan Tate, recently the night editor for Gawker. Both reporters talked to BoomTown on Friday about the changes.

MediaMemo wrote on Monday about Condé Nast shutting down Portfolio–both the print magazine and the accompanying Web site. On a cautionary note, MM outlined the reasons why Portfolio’s business magazine peers should not celebrate the loss of a competitor, even (or especially) during tough economic times. Is the meteoric ascension of Twitter flattening out? According to a Nielsen Online study, 60 percent of Twitter’s users leave after a month. This was met with a lot of skepticism so Nielsen ran the numbers again with the same results–and this time it’s sticking with them. MediaMemo also had an explanation for why the long-awaited deal between Disney (DIS) and Hulu took months and months and millions of dollars to finally come together. Digital Daily had more on that story.

Digital Daily also had more info on the ever-evolving Palm (PALM) Pre story. First, a rumor that Palm plans to launch the handset on June 7–which would be crazy, given the fact that June 8 is both the first day of Apple’s (AAPL) Worldwide Developers Conference and the day that those in the know expect the next-generation iPhone to drop. Then, there’s an assertion by Collins Stewart analyst Ashok Kumar based on supply chain research that Palm has greatly reduced its production numbers. Time will have to tell, though, because Palm certainly isn’t talking yet. Of course, things could be worse. Dell (DELL) hasn’t even solidified plans for its rumored smartphone, and already, no one really cares.

Dell’s new Adamo laptop and Studio One 19 desktop aren’t causing much excitement either. In this week’s Personal Technology column, Walt Mossberg reports that although both machines look good and function well, neither is groundbreaking. In Mossberg’s Mailbox, Walt answered readers’ questions about improving performance on a PC, using peripheral devices with an iPhone and installing Apple’s OS X on a Windows machine. And in this week’s Mossberg Solution, Katie Boehret tested three apps from the iTunes App Store that make it possible for the iPod touch to function like an iPhone.

More next week.

That’s a lot of Superpokin’….

Apparently our self-righteous outrage over Facebook’s tweaks of its Terms of Service or claims that social networks are haunted by sexual predators has done little to dampen our enthusiasm for them. “Social networking has become a fundamental part of the global online experience,” said Nielsen Online CEO John Burbank in one of those “Fire: Hot, Bread: Good” announcements. “While two-thirds of the global online population already accesses member community sites, their vigorous adoption and the migration of time show no signs of slowing. Social networking will continue to alter not just the global online landscape, but the consumer experience at large.”

Unfortunately for the companies playing in the space, social networking hasn’t yet done the same for the advertising experience. Indeed, as Nielsen notes, “The current level of advertising activity on social networks isn’t consummate with the size–and highly engaged levels–of the audience.” Nor will it be, unless the sites figure out a way to exploit the personal data of their users without making them feel like their privacy has been invaded. Nielsen’s big idea for achieving that goal: trial and error. “New approaches to the ad model are required for this challenging and complex arena,” the company explains. “It will take time to work out the magic formula for successfully advertising in social networks. The diversity and personalised nature of the environment means standard ad models–such as contextual search and standard unit sizes–won’t cut it. Different approaches across ad units and ad inventory will have to be tried, involving a trial and error mindset.”

Trial and error, eh? That’s been Facebook’s strategy hasn’t it? And as I recall, it hasn’t exactly been working out too well…

An impressive showing. And though increased traffic to online retail sites doesn’t necessarily translate into increased spending, Nielsen touts this metric as evidence that consumers are firing up their browsers, credit cards in hand.

“Even with the weakening economy, an unstable stock market and a rising unemployment rate, Black Friday traffic to online retail sites grew at a double-digit rate this year,” said Ken Cassar, vice president, industry insights, Nielsen Online. “Consumers are continuing to shift their holiday shopping to the Web for the convenience of not having to fight the crowds and to further stretch shrinking budgets. The fact that the Shopping Comparison/Portals category was the second fastest growing segment indicates that consumers continue to see the Web as the source for determining the best deals and prices of the season, which we expect to be top of mind for holiday shoppers this year.”

Now, in all likelihood that’s the case. Still, it’s worth noting that Nielsen’s top-ranked Black Friday site was eBay (EBAY), a site visited as often by people looking to sell things as buy them.

How many of the 9.8 million consumers who visited the online auction site on Friday were looking to sell something off for some extra holiday spending money, or simply to make ends meet?

It seems that morbid interest in the stock market’s decline is driving up Yahoo (YHOO) video streams, as well. The much diminished Internet major claimed 265 million video streams in September, a 56 percent increase over the 169 million it claimed in August. And that puts it in the No. 2 spot on Nielsen Online’s monthly VideoCensus. Impressive, no? Presumably, October will be even better, given the upcoming presidential election.

That said, as in search, Google (GOOG) is the one to beat in Web video. The company’s YouTube property served up an astonishing 5.3 billion streams.

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None of this has helped. None of it has bolstered Microsoft’s laggard search service, which continues to toddle along behind Google (GOOG) and Yahoo (YHOO)–a very distant third in the search market. In fact, MSN/Windows Live seems to be suffering from the company’s efforts. According to Nielsen Online’s MegaView search ranking for July, searches on MSN/Windows Live declined 2 percent month-over-month and 10 percent year-over-year. Its July 2008 share of the search market: 11.9 percent. Meanwhile, Google gained a share point from June to July, claiming 60 percent of the eight billion searches conducted during the month. And it posted 16 percent year-over-year growth, more than five times the overall growth in search.

Clearly, Microsoft’s efforts to draw users to MSN/Windows Live has yet to make much of a difference in the search share race. Nor have the efforts of other companies. Searches on Yahoo dropped 11 percent year-over-year, leaving the company with a 17.4 percent market share. AOL’s (TWX) fell 9 percent over the year, leaving it with 4.6 percent market share. And Ask.com’s (IAC) rose 13 percent, leaving it with 2 percent share, Nielsen said.

Which begs the question: Is Facebook nearing its saturation point? Is enthusiasm for the social-networking phenom finally wearing off? Have we all been spammed by the ironically named “Funwall” one time too many? Are the site’s privacy issues finally taking their toll? Or are its zombified members too busy seeking human flesh to bother updating their profiles?

Or were they simply on winter holiday?

That last scenario seems the most obvious explanation. December and January are the months at issue here. And Nielsen’s figures show that there are 712% more Facebook users than a year ago. Still, this is the first drop the firm has recorded in Facebook’s user numbers in the U.K. since the site became large enough to track. There wasn’t a similar drop in usage last year. Or the year prior. So maybe there is something more here. The early beginnings of a long-term erosion, perhaps?

“One month of falling audiences doesn’t spell the decline of Facebook or social networking,” said Nielsen’s Alex Burmaster. “However, most of the leading social networks are less popular in the U.K. than they were a year ago. It was inevitable that early growth rates couldn’t be sustained and the larger networks have been plateauing over the last few months.”

Seems the leading social networks to which Burmaster refers were also less popular in the U.S. According to the latest stats from comScore, Facebook attracted 33.9 million unique visitors stateside in January–down 2% percent from 34.7 million in December. That’s a decline of approximately 800,000 users. Again, this drop could also be chalked up to Seasonal Facebook Defection Disorder. Or not. After all, it’s not like we haven’t seen this sort of thing before. Remember Friendster?

UPDATE: Facebook disputes Nielsen’s metrics. “The number of users for Facebook continues to climb in the U.K.,” the company said. “Our internal monthly active user numbers rose between December and January in the U.K. and are now at more than 8.3 million. Facebook tracks active monthly users, rather than registered users or unique visitors. Active users reflect those who have used the site in the past 30 days.”