Well, that was brutal. As if this year hadn't started off bad enough for the broader market, LinkedIn (NYSE:LNKD) just made it undeniably clear that this 2016 will not be for the faint of heart. The professional social network saw shares plunge by 44% on Friday following its fourth-quarter earnings release.

What caused the plunge? Could it really be that bad?

Can I get your digits?
The fourth-quarter results alone weren't all that bad. Revenue jumped 34% to $862 million, and adjusted EBITDA was $249 million, or 29% of revenue. Non-GAAP net income came in at $125.7 million, or $0.94 per share. Both top- and bottom-line results were notably better than the Street's expectations of $857 million in revenue and an adjusted profit of $0.78 per share.

LinkedIn's global member base also grew to 414 million. Thanks to continued focus on apps and content, engagement is on the rise, too. Page views per unique visiting member increased 17%, and mobile continues to be the preferred method of access for the service. By most metrics, the fourth quarter was a solid one, but guidance was the real kicker.

Here's the bad news
Revenue in the first quarter should be right around $820 million. The Street was expecting $868 million. Full-year 2016 sales should be in the range of $3.6 billion to $3.65 billion. The Street was expecting $3.9 billion.

There's no question that LinkedIn's outlook left something to be desired relative to consensus estimates, but even still it hardly seems warranted for shares to lose nearly half of their value overnight.

Adjusted earnings per share in 2016 are expected to be in the range of $3.05 to $3.20, which represents 10% earnings growth at the midpoint. That undoubtedly represents deceleration, which typically punishes high-multiple stocks like LinkedIn, but investors were already expecting that deceleration. It's just a bit worse than expected.

What now?
At the end of the day, what matters most to investors is what happens now. Is this drop really a buying opportunity in disguise? Or is it part of a painful price discovery process where LinkedIn's prior overvaluation becomes clear?

I've long believed that LinkedIn's premium valuation is justified, considering its unique positioning and differentiation within the social media sector. Plus, it has a more resilient business model that does not rely solely on advertising revenue. Following the drop, shares now trade at just 5.1 times sales, compared to Facebook's 16.5 sales multiple. Meanwhile, LinkedIn is still only starting with certain opportunities like China, which remains the fastest -growing market in terms of new members.

A little bit of disappointment regarding LinkedIn's guidance is justified, but I think the market reaction is overdone. Chances are we'll look back in a few years and see that this drop turned out to be a buying opportunity.

Evan Niu, CFA owns shares of Facebook and LinkedIn. The Motley Fool owns shares of and recommends Facebook and LinkedIn. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.