Experiencing significant growth, some are asking whether question & answer service Quora can keep up the quality of its content. "The site depends on high-quality answers, and has deliberately kept things small in order to cultivate a knowledgeable community," writes GigaOm's Matthew Ingram. "But can it keep those virtues when membership is exploding and not everyone wants to play by the rules?" As Ingram notes, many services have failed to overcome what Robert Scoble calls the "chatroom problem," or fallen into what Gartner artfully calls a "trough of disillusionment." Another way to think of it is the …

To better prevent spam -- and having legitimate messages lost in recipients' spam folders -- Google is adding an extra layer of email authentication for Google Apps. As eWeek reports, all Google Apps users can now sign their outgoing messages with DKIM -- DomainKeys Identified Mail -- so that their mail is less likely to get stopped by recipients' spam filters. DKIM ties a domain name to an email, allowing an organization to take responsibility for a message in a way that can be validated by the person receiving it. "The capability is being offered at no …

Sure to upset the social networking ecosystem, LinkedIn is reportedly planning to go public before the end of the year. Sources tell Reuters -- which broke the news -- that the name of the game is beating Facebook to the punch. "Some of these companies want to go public because they want to beat Facebook and others out," one source tells Reuters. "If Facebook went public before Linkedin, do you think anyone would pay that much attention to Linkedin?" Indeed, "If Facebook goes public, it could be such a massive …

CBS has agreed to let Boxee sell TV episodes through its software platform beginning sometime this year. The New York Times' Gadgetwise blog calls the deal "a step forward for television episode sales." Announced at the Consumer Electronics Show in Las Vegas, the partnership represents the first content deal between Boxee and a major television network. "Boxee is one of several companies that wants to bridge television and the Internet, and it is hungry for deals with content providers like CBS," Gadgetwise points out. Indeed, "It's a major step for us, working with the biggest network in …

eBay's global mobile sales generated nearly $2 billion in 2010, up from $600 million in 2009, according to the ecommerce giant. "We're not talking revenues here but gross merchandise volume," notes TechCrunch. "Nevertheless, a clear sign that mobile ecommerce has reached a tipping point." Year-over-year, global mobile sales were up 166% to $230 million between November 25 and December 25, according to eBay. "So," writes TechCrunch, "the holiday season was a clear catalyst for much of that growth." According to eBay, its mobile apps have been downloaded more than 30 million times in eight languages, and in …

Top social gaming company Zynga has acquired social browser Flock. Financial terms of the deal were not disclosed, but Flock has raised around $30 million in funding since it launched in 2005. Flock integrates services like YouTube, Digg, Facebook, and Twitter into a single browser, along with baked-in tools for editing blogs and uploading photos. According to CNNMoney, Flock "has a cult user base of 10 million, but was upstaged earlier this year by the splashy launch of rival RockMelt, which shares essentially the same vision for a social browser." In a blog post, Flock CEO Shawn Hardin claimed …

Despite several billion dollars in an equity offering likely to reach $1.5 billion, Goldman Sachs doesn't have nearly enough Facebook shares to go around. The Wall Street Journal likens the situation to "the technology bubble of the late 1990s when online-grocery seller Webvan Group Inc. and other upstarts with far shorter track records than Facebook sold stakes to investors." Furthermore, The Journal calls Goldman's predicament "a sign of investor fascination with the closely held social-networking company despite a dearth of available information about its operations and financial condition." According to people familiar with a stock-offering document, Facebook …

Skype has reportedly acquired mobile video streaming technology provider Qik for about $100 million. According to Business Insider, Skype and Qik share influential startup investors Marc Andreessen and Ben Horowitz, which it assumes "helped get the deal done." According to Qik, the company started the year with 600,000 users and ended with 5 million. "The huge bump came in large part thanks to partners like Sprint, T-Mobile, Nokia, and Samsung," Business Insider notes. "That makes the hero of today's deal a guy named Bob Rosin, the company's EVP of business and corporate development. He's the one who …

Goldman Sachs, which just invested $450 million in Facebook, claims that the social net now has north of 600 million active users. Goldman, which is in the process of offering clients $1.5 billion worth of Facebook's common stock, has every reason to inflate the network's numbers, but the estimate sounds about right. Facebook said it crossed the 500 million monthly active user threshold this past July, and its official stats page says there are "more than 500 million active users" on the site. "Now we know there are at least 100 million more," notes Business Insider. "It's …

Mobile ad network Millennial Media, just raised another $27.5 million from Bessemer Venture Partners, along with Columbia Capital, Charles River Ventures and New Enterprise Associates. The Baltimore-based company has already raised $65 million, but, as eMoney notes, "That hardly seems sufficient when fighting Goliaths like Apple and Google, which both made multimillion-dollar acquisitions last year in the space." According to eMoney, Millennial is presently considered by many to be the largest independent mobile ad network in the United States. The funds are earmarked for acquisitions in 2011, along with investments in the company's international business. To date, …