Facebook (META 0.73%) and Twitter are riding a massive wave of worldwide smartphone and tablet adoption. As their sales soar, should Google (GOOGL 0.54%) be worried? Probably not, says Fool contributor Daniel Sparks, as he speaks with Fool.com's Erin Miller in the video below. But investors should keep an eye on the mobile strategies these companies pursue, since it will inevitably play a very important role in their future success.