The catchy rumor ahead of Facebook’s initial public offering filing was that the company’s record IPO will create 1,000 millionaires overnight.

With a current plan to raise $5 billion in its stock sale — the largest Internet IPO in history — employees who were granted stock options in Facebook when they were hired certainly have a lot to gain. The Daily Mail reported that the company will have “well over a thousand” employees who will be millionaires after the company goes public, based on comments from an anonymous former in-house Facebook recruiter.

It is clear that Facebook’s IPO will add substantially to the wealth of its board members and top executives, who are already millionaires or, in the case of chief executive Mark Zuckerberg, billionaires.

But the answer is, really, that’s it’s impossible to know how many of the company’s 3,000-plus employees will see their personal wealth hit that coveted seventh digit without knowing what compensation packages Facebook has given out to its rank-and-file workers.

On Quora, the question-and-answer site, one anonymous poster has said that a lot of Facebook’s newest employees are paid hourly and don’t have stock options, with the exception of high-value hires or those whose companies were acquired by Facebook. Another post from Adam Oliveri, who studies the IPO market, said that he believes that many of the employees are already millionaires, based on their existing compensation packages.

Over at the Wall Street Journal, wealth blogger Robert Frank tackled the question in a post ahead of the IPO, and came to similar conclusions, based on news reports of Facebook’s compensation packages.

And, Frank notes, although we can speculate on whether any newly made millionaires will flourish when the company makes its market debut, there’s no telling what the price for a Facebook share will be by the time they can sell their shares — likely in the middle of 2013.

The largesse will not be limited to Facebook employees and directors. One member of the board, Post Co. Chairman and chief executive Donald E. Graham, said in a statement that eventually, when he leaves the board, he will donate his shares to “two or three D.C. education-related charities I’ve supported over the years.”

“Thus, a small portion of Facebook’s success will be shared with low-income students in Washington,” Graham’s statement says. The statement emphasized that Graham — who holds 1 million restricted stock units — won’t be selling any shares as long as he remains a Facebook director.

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