[caption id="attachment_61844" align="aligncenter" width="607" caption="Jeff and Mackenzie Bezos (Credit: Bloomberg)"][/caption]

Amazon.com founder and CEO Jeff Bezos and his wife Mackenzie pledged a whopping $2.5 million to Washington United for Marriage, a group backing Referendum 74 which puts a marriage question on the ballot in November. As the largest single donation to marriage equality in history, the billionaires' generosity nearly doubles the funds collected by the campaign.

The New York Times reports that Mr. and Mrs. Bezos got a little push from a former Amazon employee and lesbian mother of four who asked the 13th wealthiest man in America to donate $100,000. “We need help from straight people. To be very frank, we need help from wealthy straight people who care about us and who want to help us win,” wrote Jennifer Cast in an email. Cast, who worked under Bezos when Amazon had only a few dozen employees, is now a fund-raising chairwoman of the pro-referendum effort.

Unsure how her former boss would respond, she told the Times she had never dicussed same-sex marriage with him, having left Amazon in 2001:

In the e-mail, Ms. Cast described in detail the pain she endured as a young adult and the difficulties she faced publicly acknowledging her sexuality. At the end, she pointedly asked him to donate between $100,000 and $200,000 to the referendum cause.

“Jeff, I suspect you support marriage equality,” she wrote. “I beg you not to sit on the sidelines and hope the vote goes our way. Help us make it so.”

She hit “send” and waited.

Two days later, on Tuesday, she received a reply while in a car with her family. Recalling that moment, she said she had to read it out loud twice to make sure she had read it right.

“Jen,” the e-mail said, “this is right for so many reasons. We’re in for $2.5 million. Jeff & MacKenzie.”

Hey, Bill Gates, Steve Ballmer, thanks for your $100,000 donations earlier this month, but it looks like your billionaire buddy Bezos has upped the ante.