The companies seeing the strongest growth—Apple and Facebook—are the ones with the most successful mobile strategies. The companies seeing declines, missing expectations, or falling short of their former glories—Google, Alibaba, and Microsoft—are the ones that can't quite make mobile work for them. And in that faltering, opportunity opens up for the next great business idea—an idea not weighed down by the legacy of the desktop.

Yes, these are all huge companies with many moving parts that make the math behind their business successes and failures complex. But sometimes, applying Occam's razor can be instructive.

Take Apple. It pretty much invented the current iteration of mobile as a category—as a business all these other companies had to bother to figure out in the first place. It makes the hardware that people want to always have with them. And on Tuesday, it posted the biggest quarterly profit by a public company in corporate history.