LinkedIn has filed a registration statement with the Securities and Exchange Commission, setting the stage for the professional-focused social networking site to go public. 
 
 Though the company does not reveal a price, number of shares, or date for its offering, it does offer insight into its financials. LinkedIn generated $120 million in revenue for 2009, and $161 million through the first nine months of 2010, where it also turned a profit with a net income of about $10 million. 
 
 That revenue comes from three sources — advertising, job listings and premium subscriptions. The latter has declined significantly as a revenue source since 2007 (from 53% of sales then to 27% through the first nine months of 2010) while job listings and advertising have become the company's primary growth areas (41% and 32% of revenue, respectively). 
 
 In its filing, LinkedIn notes that Facebook, Twitter, Google and Microsoft are all potential competitors, writing that they "could develop competing solutions or partner with third parties to offer such products." That said, the company finished 2010 with more than 90 million members, and claims to be adding 1 per second in its filing. 
 
 Recently, private trading of LinkedIn shares valued the company at nearly $3 billion. That would make the company's debut bigger than that of Demand Media, which went public on Wednedsay at a valuation of around $1.5 billion. With Skype, Groupon and potentially Facebook also in the mix of IPO candidates this year, LinkedIn's offering will be another big barometer for the public's appetite for Internet IPOs. 

 A name change, not making any money, a lot of debt: If that description sounds like a recipe for a dicey online date, then investors might want to apply the same principles to the coming week's IPO of Web-site operator FriendFinder Networks Inc. 
 
 View Full Image none needed A FriendFinder page: 'social networking' but not exactly Twitter. The page includes a link at top-center of the page to IPO information. 
 
 FriendFinder, which operates more than a dozen Web sites aimed primarily at people looking for relationships or flings, changed its name 18 months ago from Penthouse Media Group. It isn't profitable, and until recently was in default on its debt covenants. 
 
 It struck a deal in October with its creditors to waive its defaults in exchange for all the money it raises in its initial public offering. 
 
 It is hoping for $200 million in net proceeds from the sale of 20 million shares through RenCap Securities and Ledgemont Capital Markets LLC, according to its prospectus, with an estimated price range of $10 to $12, and a listing on the New York Stock Exchange with symbol FFN. 
 
 The company is portraying itself as a potential catch in the social-networking industry, a sector that has few stand-alone stocks and a lot of buzz. It describes itself as a leading "social networking and multimedia entertainment company," and in prerecorded roadshows compares itself with privately held Facebook Inc. and MySpace, owned by News Corp., publisher of The Wall Street Journal. 
 
 But FriendFinder differs from both: Members on Facebook and MySpace tend to keep their clothes on, while several of FriendFinder's sites encourage the opposite. 
 
 Though the firm does operate several general-interest dating sites—FriendFinder, BigChurch.com and SeniorFriendFinder.com—its largest is AdultFriendFinder.com, which targets swingers and people who want to meet, according to the Web site, partners "tonight." 
 
 Executives at FriendFinder are somewhat circumspect when it comes to describing their Web sites in the company's prerecorded roadshow, available at RetailRoadshow.com. 
 
 The company's dark-suited, bespectacled chief executive, Mark H. Bell, describes one of the Web sites, GetItOn.com, as a fast-growing new site that allows people to text search and "type in a sentence like, 'I'm looking for people who ride motorcycles.' " 
 
 Mr. Bell didn't return a call seeking comment on the IPO. 
 
 FriendFinder isn't exactly the kind of social networking that most investors have in mind when they talk about a site like Twitter or LinkedIn someday going public, says Josef Schuster, founder of IPOX Schuster LLC, a Chicago financial-services firm specializing in IPO products. 
 
 Aside from some of the racy content on FriendFinders' sites, the $471 million of debt the company carries makes it look more like a leveraged-buyout turnaround than a high-growth new-media prospect, Mr. Schuster says. 
 
 FriendFinder also differs from MySpace and Facebook in its business model: Most of its revenue is generated by converting casual viewers into paying subscribers, not advertising. 
 
 While subscription-based revenue is more predictable than advertising, it has been affected by global economic conditions, and net revenue remained flat at $244 million in the first nine months of 2009, compared to the same period of 2008. The company's net loss narrowed to $27 million from a loss of $32 million a year earlier. The company plans to increase its focus on driving more advertising revenue in the future, according to its prospectus. 
 
 Because many of its sites focus on particular tastes—be it a spiritual Christian wife or a casual fling with a sadomasochist—the subscriber model does make sense, says Michael Gartenberg, vice president of strategy and analysis at market research firm Interpret LLC. 
 
 "If you have more eclectic tastes that go beyond what might come up in polite conversation, it could be hard to find people with similar interests using traditional social sites," Mr. Gartenberg said. "These are the folks who would be the people most likely to pay for a subscription service in order to match with someone who shares their particular interests and needs." 
 
 FriendFinder isn't being shy about marketing its IPO, either. Besides doing a roadshow for investors, it has sent out blast emails to its employees, affiliates and the various sites' members telling them how they can participate in the stock offering. 
 
 Write to Lynn Cowan at lynn.cowan@dowjones.com
– After weeks of speculation, LinkedIn has confirmed what many suspected—it will go public later this year. The career-focused social networking site filed a registration statement with the SEC yesterday, setting the stage for the company to become the biggest social network yet to land on Wall Street, reports Mashable. With revenues of $164 million in the first nine months of 2010 and 90 million users, LinkedIn is one of the biggest social networks this side of Facebook, and financial observers are keenly watching its IPO for a sense of broader market demand. Experts say 2011 could be a big year for social networking websites going public. "Facebook has definitely escalated people's interest in the sector and I think there's a lot of demand (for more Internet IPOs)," said one analyst. Friend Finder Networks, the company behind the smutty hookup site Adult Friend Finder, filed its intention to go public last week. However, with the company's subscription-heavy revenue model, $471 million in debt, and risque content, FFN is considered a more unusual case.