If LinkedIn (NYSE: LNKD) is part of the new dot-com bubble, at least it's validating those that have risked derision and sudsy complexions by blowing it higher.

The social networking site for professionals delivered blowout quarterly results last night. Revenue soared 120% to $121 million, well ahead of the $104.7 million the pros were targeting. LinkedIn earned $0.04 a share -- or $0.10 a share on an adjusted basis -- during the quarter. Wall Street figured LinkedIn would check in with a small loss.

The publicity of LinkedIn's IPO has clearly helped give the site a viral push. There were 115.8 million members on its site, a 61% improvement over its registered user count a year earlier.

Cynics who have argued that LinkedIn has been slow to monetize its white-collared website should cut LinkedIn a break. It finally generated more in quarterly revenue than its member count.

Key gauges show LinkedIn is getting its users more engaged. Unique monthly visitors popped 83% to 81.8 million. It served up 7.1 billion pages during the quarter, 80% ahead of last year. It's great to see both of those metrics growing faster than the site's membership base.

LinkedIn isn't simply about slapping ads on a gargantuan number of page views the way investors view larger social rival Facebook. LinkedIn's monetizing opportunities rest in catering to its career-minded users. Hiring solutions account for nearly half of LinkedIn's revenue, and premium subscriptions are good for a nearly 20% chunk of the revenue.

Investors have been flocking to social networking sites ahead of Facebook's inevitable IPO. China's Renren (NYSE: RENN) and Latino-targeting Quepasa (AMEX: QPSA) have had their ups and downs.

Then again, maybe it's not fair to lump LinkedIn with international social networking sites, and not because all but a third of its revenue is generated domestically. LinkedIn's network referrals and job leads may make it a better fit with web-savvy recruiting hubs such as Dice Holdings (NYSE: DHX), Monster Worldwide (NYSE: MWW), or China's 51job (Nasdaq: JOBS).

Is LinkedIn really worth its roughly $10 billion valuation? Any rational investor would tell you that it's clearly overvalued, but it's hard to bet against a company when it's growing this quickly and has all of its viral metrics clicking.

LinkedIn is moving pretty fast these days. If you want to keep up, add it to our free My Watchlist service that delivers up-to-date news and analysis on your favorite companies.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.