Google boss Larry Page has partially paralyzed vocal cords, which forces him to speak in a near whisper. Twitter and Square co-founder Jack Dorsey once wore a nose ring and dreadlocks and favors a frenetic-sounding management approach to that seems to involve a lot of walking meetings. Ultra-focused Mark Zuckerberg, in contrast, wears the same T-shirt everyday has described himself as "the least cool person there is."

My point is this: these are three very different guys. Yes, they've all built massively successful tech companies, but when it comes to leadership (and personal) style their approaches are from from uniform.

But according to one veteran engineer who has managed to work with all three during the course of his impressive career, there's at least one practice that unites all these leaders. There is "a very specific behavior that I have observed all three CEOs exhibit," Gokul Rajaram, who is currently a product engineering lead at Square, writes on Medium. "In short, they completely avoid saying a certain word."

You'll never guess the word these CEOs all avoid.

Go ahead, take a minute and guess the word. I'll wait. But I'm willing to wager that no matter how long I give you and no matter what you come up with -- whether it's an inspirational omission like refusing to say "impossible" or a culture-building prohibition such as banning "because I said so" -- you won't land on the right answer.

Why? Because the right answer is borderline unbelievable.

According to Rajaram the word all these CEOs refuse to say is one that most of us think of as central to competent business leadership: revenue. Yes, revenue.

Wait, that's crazy!

How is that possible, you're probably asking? Isn't the whole point of a company to make money, ie. generate revenue? But Rajaram insists that, with the obvious exception of earnings calls and perhaps the odd slip of the tongue, these leaders studiously avoid discussing revenue with employees and in internal meetings.

Why make revenue as unmentionable as Voldemort? "All three implicitly understood this fundamental truth from Day 1 of founding their respective companies: revenue is a lagging indicator. Revenue is a natural outgrowth of doing the right things on every other dimension that matters," writes Rajaram.

Instead of framing winning as bringing in more money, these leaders all frame winning as building market share, serving customer needs, or acquiring users. Revenue, it's silently understood, will flow from there.

Check out the complete post for several fascinating stories from Rajaram's career at Google, Facebook, and Square that illustrate his point, but his essential advice for business leaders aiming for greatness boils down to this: "Revenue is a crutch. Talking about revenue is a shortcut for discussing the things that truly matter. Don't take the easy way out. Frame goals in terms of the things that matter, the leading indicators of revenue."

Do you think this advice applies broadly or only for certain types of tech companies?