You can't discuss smartphones and tablets without coming back to Apple (NASDAQ:AAPL) and Samsung. The two giants are crushing the mobile market with impunity, owning about half of the world's device sales between them (not to mention all of the mobile profits).

But why should investors bother to look at market share figures? Isn't the mobile industry big enough for the two of these dueling cowboys -- and more besides?

In this video, Fool contributor Anders Bylund explains why market share matters, but maybe not for the reasons you thought. This is not a game of thrones as much as it is a battle for survival if you're not part of the ruling class. That's bad news for BlackBerry (NYSE:BB) as well as the odd couple of Nokia (NYSE:NOK) and Microsoft. The only time the king really matters is when there are no dukes getting within grabbing distance of his crown. Look to Netflix (NASDAQ:NFLX) for a modern example of this. In both cases, life is exceedingly hard for the little guys.