Consider each company relative to Apple.
Hewlett-Packard (HPQ). I said about all that needs to be said in Hewlett-Packard Needs to Stop Selling Computers. If selling low-end hardware and phablets is the right strategy for a lost tech company, I want to be wrong. (Set to the tune of If loving you is wrong, I don't want to be right).
Best Buy (BBY). This has been the biggest gift of 2013 on Wall Street. See Sell Best Buy, It Has No Pulse. It's an insult to our collective intelligence when a company like Best Buy, not worthy of selling Apple's leftovers, can even sniff AAPL's performance.
First, in and of themselves, I'm not dissing either company. I don't consider them overvalued per se and I believe in the prospects of their respective businesses. I might not be the most bullish, but I'm definitely not bearish. Consider what I am saying here within the context of a comparison to Apple.
Having observed Facebook's advertising platform and news feed closely on both mobile and the desktop, I honestly don't think the company has any idea what it wants or how to do what it's unsure of. It's the classic case of throwing algorithms against the wall to see what sticks.
Ever since Facebook tweaked its news feed algorithm to be more relevant and a purveyor of news (something it ought to leave to Twitter), mine has become a mess.
As much as I love my employer, I don't want 11 stories in a row from TheStreet, interspersed with another 10 or 20 from Business Insider and Buzzfeed, to come in between status updates from a handful of my friends. You can smell that there's no rhyme or reason at Facebook from a mile away.
That might not be a bad thing. There's nothing wrong with experimenting on your audience until you find the sweet spot. But, again, relative to the structure at Apple, I'm not sure how you can justify 38% upside in FB versus just 13% for AAPL in 2013 (using a one-year chart, as of December 26, 2013).
Something similar stands for Twitter.