Sheryl Sandberg has been described as the "grownup" at Facebook since she joined the company as the chief operations officer. Mark Zuckerberg told an interviewer last year that Sandberg handled all the things he didn't want to do like human resources, marketing and the other operations tasks that are a mandatory part of doing business.

SEE: Top Female Executives And CEOs

Sandberg has been instrumental in Facebook's success since 2008, but it was only in June that she was asked to join the company's board. In a press release, Zuckerberg described the logic behind the invitation: "Sheryl has been my partner in running Facebook and has been central to our growth and success over the years .… Her understanding of our mission and long-term opportunity, and her experience both at Facebook and on public company boards makes her a natural fit for our board."

Perfect Fit for Facebook
This won't be her first board position, either. Sandberg serves on the boards of both the Walt Disney Company and Starbucks, as well as a host of other organizations. There's no doubt that Sandberg's skills and hard work make her a perfect fit for the Facebook board. Her background stint at Google as vice president of global online sales and operations after serving as chief of staff for the U.S. Department of the Treasury is par for the course among the other seven members of Facebook's board.

Sandberg is also credited with figuring out how to make Facebook profitable, by convincing the company's leadership that advertising was a viable option and then by putting the monetization plan into action. A little less well known is how Sandberg made some major changes to the frat boy culture that prevailed at Facebook before she was hired. Katherine Losse, who joined Facebook in 2005, chronicled her time there in a recent memoir, "The Boy Kings," including describing a number of harassment issues that went unaddressed until Sandberg joined the leadership.

There are questions about the timing of Sandberg's election to Facebook's board. Over the past year, there have been many pointed questions about the lack of women on both the boards of tech companies in general and on Facebook's board in particular. Sandberg, as the eighth member of the board, is the first woman elected to it. Zuckerberg's response a year ago was that the company had a particularly small board and that, "I'm going to find people who are helpful, and I don't particularly care what gender they are or what company they are. I'm not filling the board with check boxes."

Lack of Women
In March, protesters gathered at Facebook's New York headquarter to demonstrate against the lack of women represented on the board. Individual investors have written letters encouraging the company to add diversity to the board. Other protests and criticism, including of Facebook's handling of its initial public offering, have built into a growing sense that Facebook was under attack. The company is facing lawsuits for how the stock offer was handled.

The Bottom Line
Sandberg deserves her seat on Facebook's board in her own right. Her business credentials are impeccable, and she's taken a stand as an advocate of women taking leadership roles in business. The company's move towards greater diversity also will serve to build a stronger business overall. With the addition of Sandberg to Facebook's board, it's only to be expected that the company will continue to evolve.

SEE: 5 Richest Women In The U.S.

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