From economics major to ebay CEO: a Princeton alumna gives back. (Update).

Here's a little piece of advice that might pay off big-time one day: Make sure every student on your campus has a memorable college experience, and never neglect your alumni. After all, you never know who's going to be the next Bill Gates, Donald Trump--or Meg Whitman. In February, Whitman (president and CEO of eBay, Inc., the online auction house) made a tidy little gift of $30 million to her alma mater, Princeton University.

"I had a great time as a Princeton undergraduate," the former economics major told the media. "The university inspired me to think in ways that have guided me throughout my life. I'm pleased that I can help bring Princeton to more students and that my gift will benefit the university for generations to come."

In fact, Whitman's gift will permit the university to proceed with plans to build a sixth residential college and expand the student body by 10 percent. But this is not the first time the eBay CEO has turned her attention toward her alma mater: She has served as a university trustee since 2000, and is a member of the board's Executive Committee. Whitman also puts her muscle behind the school's athletics initiatives. (She was a member of the lacrosse and squash teams.)

As Princeton's spokespeople have said, the school's recent decision to help fund its students' college education by substituting grants for loans is not purely altruistic, but an investment in the future. Considering the size of the gifts coming in from successful Princeton grads, that may be the understatement of the year.