In the two years since its rocky initial public offering, Facebook has become a strong business that regularly releases financial results that set investors' hearts aflutter. Despite every hipster prediction otherwise, the company's user base keeps growing, and nearly a fifth of the time that Americans spend on their smartphones is spent on Facebook. That surpasses the amount of time we spend on any other single service by a wide margin—and beats just about anything else we do on our phones, or perhaps in our lives, period.

And yet, when was the last time you swooned over some new feature in Facebook? The two big products that Facebook unveiled last year—Home, an Android lock screen, and Graph Search, a search engine—failed to catch on. And some of the most innovative recent social networking ideas have come from upstarts, which Facebook has either spent huge sums buying (up to $19 billion for WhatsApp, $1 billion for Instagram) or trying and failing to buy ($3 billion offered for Snapchat).