To celebrate its 13th straight year of being named to Fortune magazine’s “100 Best Companies to Work For” list, Plante & Moran, PLLC, challenged partners and employees to spread the word via a Facebook status update that announced the honor and linked through to a survey of 15 local women’s shelters the firm supports.

Once Facebook friends clicked the link, they could vote for which shelter they wanted to receive an additional $1,300 through the firm’s Plante & Moran Cares initiative.

“Our original plan was to award one $1,300 prize to commemorate our 13th win,” said Plante & Moran Managing Partner Gordon Krater in a statement. “We had such an overwhelming response—4,294 people visited the survey and 3,403 completed it—we decided to award the four top vote getters with donations ranging from $100 to $1,300.”

SafeHouse in Ann Arbor, Mich., received the most votes, with 1,101. Domestic violence shelters are the current focus of Plante & Moran Cares, the firm’s charitable outreach arm, which chooses a different charitable category to support every fiscal year.

The firm’s 26th ranking on Fortune’s list was not the first internal development spread through social media.

“We regularly encourage staff to share firm announcements to their Facebook friends to help us tell the Plante & Moran story,” said Chief Marketing Officer Jeff Antaya in a statement. “To add Plante & Moran Cares to the message meant a whole new level of engagement among staff that was heartening to see and ultimately proved to be a new way to reinforce our caring culture.”

Plante & Moran employs 1,600 people in 21 U.S. and three international offices.