Look at that. Mobile hugely up, and personal computer usage for Facebook is actually down.
Take heed, and ignore this trend at your peril. Mobile isn’t the future anymore. It’s the present.
And I’ll just add that while there’s recently been quite a bit of talk about going back to “web first”, Facebook’s numbers are especially important here. Yes, a lot of early adopters are still heavy traditional web (meaning desktop/laptop-based) users. But Facebook is at full mainstream scale with a billion-plus users and the trend is clear. If you’re thinking big and for the future, you have to think mobile.