It's a milestone day for the mobile world: Android's internet use has overtaken that on Windows PCs for the first time. According to StatCounter, Google's phone platform represented 37.93 percent of tracked internet activity in March, just barely edging out Windows' 37.91 percent. You could see this coming for a while, of course. Smartphone shipments overtook PCs roughly 6 years ago, and people have been spending more time on their phones than their computers. Still, it's a sign of just how important smartphones have become to many people -- and when you see where Android is the front runner, you'll understand why.