And then there's a gray area between those two where still other leaders fail. Call it the realm of bad personal style: an arena where the players flout mores, if not always the law, and demonstrate gross interpersonal, if not always professional, incompetence.
Lately, the ranks of those who have vanished into this career twilight zone include Julie Roehm, the fired Wal-Mart CMO; Steve Heyer, whose personal style gave him leave both from Coca-Cola and as CEO of Starwood Hotels; Harry Stonecipher, whose office amorism cost him his job as CEO of Boeing; David Edmondson, who had fudged his resume and, so, got booted as CEO of Radio Shack; and Robert Nardelli, whose imperious ways -- and compensation to match -- created a cloud of opprobrium that forced him out of Home Depot (before he recently landed as CEO of Chrysler).
"The people most susceptible to this kind of failing are those in marketing and those who've been asked to come in and shake up the status quo," said Bob Eichinger, CEO of Lominger International, a unit of the executive-search firm Korn Ferry. "They're promoted into their jobs for their business smarts and they fail because of weaknesses in their people smarts."
Jeffrey Sonnenfeld, senior associate dean for executive programs at the Yale School of Management whose latest book is "Firing Back: How Great Leaders Rebound After Career Disasters," said such blow-ups are hardly a surprise "in a highly fluid labor market where individual top-star executives have become brands in themselves. The benefits are real but so are the risks, to the companies and to those executives."
How can you make sure you don't fall into the trap that has been exposed by "branded" executives who got too big for their own breeches? A good upbringing can help. Meantime, some pointers:
EARN YOUR LEADERSHIP STRIPES EVERY DAY.Don't confuse career ascendance with divinity. You must continuously demonstrate competence, expertise, vision and honesty if you want people to follow you, said Jim Kouzes, co-author of "The Leadership Challenge" and executive fellow at the Center for Innovation and Entrepreneurship at Santa Clara University. "Leadership is a relationship," he said.
And often, how you relate to people at the bottom is one of the best indicators of whether you'll make it to the top.
DON'T ASSUME CARTE BLANCHE.Just because American culture -- where tolerance has become the paramount value -- says, "Anything goes," corporate rectitude is still saying, "Watch it!" Mr. Stonecipher learned that in 2005 when his racy e-mails to a colleague he was dating led to the 68-year-old's ouster.
"We often misattribute the permission we're given to lead by our constituents to a permission to behave however we want," Mr. Kouzes said.
And in this era of increased scrutiny on all C-level executives because of Sarbanes-Oxley, you're being held to ever-higher standards, not lower.
GIVE RESPECT TO EARN RESPECT.Even if you're being brought in as a change agent, you must appreciate the values that undergird the pre-existing corporate culture. Ms. Roehm's biggest mistake, for example, was thumbing her nose unnecessarily at parts of Wal-Mart culture that really were irrelevant to what she was hired to do: shake up marketing.
This means respecting humans, too, not just standards. "Always, always be respectful to other people," said Dennis Zeleny, former chief of HR for Honeywell and Dupont and former exec VP-administration for Caremark Rx.
BE READY TO PAY THE PRICE.Just like a politician or a porn star, being a CEO or CMO means that you've made the choice to lose some privacy. So you must make sure that all of your behavior is consistent with your company's standards and its brand.
"If you're going to assume the burdens of running a public corporation or a big part of it, you also have to pay the price," said Yale's Mr. Sonnenfeld.
WATCH OUT FOR THE MARKETING TRAP.CMOs are more susceptible than other C-level executives to fall into the limbo of bad personal style because their strengths have masked weaknesses that can bite them as they acquire broader authority.
"People with high psychic energy may not have the business acumen, or may be too narcissistic, to succeed in a P&L position," said E. Ted Prince, CEO of Perth Leadership Institute, a Gainesville, Fla., leadership-training firm.
MAKE YOURSELF ACCOUNTABLE.To help avoid all of the traps, get an executive coach or some other person who will reflect reality to you in an uncompromising way -- and, just as important, to whom you are willing to be accountable.
"You need a sounding board, and someone has to look out for you to help you avoid blind spots," Mr. Zeleny said.
PULL A 360.You can also increase your self-understanding by conducting a 360-degree review, Mr. Zeleny said. And search for feedback from a wide variety of sources.
"People who are successful get feedback from everyone, even from taxi drivers," said Rita Gunther McGrath, an associate professor at Columbia Business School. "You should have multiple ways to stay informed about how you're doing."
Dale Buss is a journalist and author based in Rochester Hills, Mich. His work has appeared in publications including The Wall Street Journal, New York Times, Chief Executive and Advertising Age.