LinkedIn (LNKD.DL), the professional networking site, expects increased mobile usage next year. In order to take advantage of this increased traffic, LinkedIn has updated its applications and partnered with Apple to integrate LinkedIn into Apple's email program.

LinkedIn pointed out the reason for this: Mobile users are simply more engaged. Mobile users are more than twice as active as those who only visit from personal computers. What are the implications for this high-flying company to have a more engaged user base?

Also, social-media companies are trading at very high valuations, particularly on a price to earnings ratio. What are the risks of valuing these growing companies on merely a price to earnings ratio? Finally, find out if LinkedIn is in Evan Niu's portfolio.

In this segment of Tech Teardown, Erin Kennedy discusses LinkedIn's aggressive mobile moves with Jamal Carnette and Evan Niu, CFA.