Amazon founder and CEO Jeff Bezos has donated $2.5 million to a Washington-based same-sex marriage advocacy group.
Bezos and his wife, MacKenzie, contributed to Washington United for Marriage, a coalition to uphold the state's same-sex marriage law.
It appears to be the largest individual donation ever to preserve gay marriage.
"The extraordinary contribution from Jeff and MacKenzie Bezos will make an enormous difference for our campaign to defend Washington's marriage law," said WUM campaign manager Zach Silk in a statement to CNN Money.
An Amazon spokesman told CNN Money that the CEO and his wife have strong feelings about the issue and felt strongly about making the donation.
Washington State legalized gay marriage in 2006, but anti-gay marriage activists gathered enough signatures in recent months to put the measure on the ballot in November.
The Seattle-based CEO's pledge comes at a time when, on the other side of the country, opposite feelings are drawing heat from not only marriage equality advocates, but the mayors of major cities.
Chick-fil-A President Dan Cathy's comments against gay marriage have created an uproar, prompting the mayors of Boston, Chicago and San Francisco to issue statements condemning the fried chicken chain.
Jena McGregor of the Washington Post noted that it's unclear now if Bezos's donation will draw the ire of conservatives who pushed for boycotts after Starbucks' top executive Howard Schultz spoke out in favor of gay marriage.