More than 640,000 thank Starbucks for supporting same sex marriage

Starbucks' headquarters in Seattle received a huge "Thank You" card on Thursday for supporting legislation that allowed same sex couples in Washington state to marry.

More than 640,000 people signed the card, which was the creation of SumOfUs.org, MoveOn.org and Washington United for Marriage.

"We knew that people would stand with Starbucks for standing up for marriage equality, but this response is amazing. This kind of consumer support shows why so many Washington companies recognize that all loving, committed couples should have the freedom to marry," said Zach Silk, Campaign Manager for Washington United for Marriage.

The groups launched their "Thank You Starbucks" campaign after the National Organization for Marriage (NOM) called for a boycott of the company. So far, only 28,631 people have pledged to boycott Starbucks for their support of marriage equality.

In January, Starbucks officially endorsed legislation to grant same sex couples all the marriage rights available to heterosexual couples.

"This important legislation is aligned with Starbucks business practices and upholds our belief in the equal treatment of partners," the company said in a statement. "It is core to who we are and what we value as a company."

Washington Gov. Chris Gregoire (D) signed that legislation into law in February. Those who oppose same sex marriage, including NOM, have vowed place a repeal of the law on the November ballot.