What's most surprising is the scale of Facebook's user testing with the navigation bar. The team says it has tested the new navigation bar with as many as 8 million users, using various iterations of the layout since March. Yet despite this widespread testing, the feature hasn't garnered widespread attention from the tech press.
Why so little notice? It's likely that Facebook is just smart enough to know who is and isn't likely to take note of such a change — but the team also believes that the new navigation bar is so intuitive that users hardly notice it: "When we did UX studies, people just don't realize that there's a tab bar there."
