memes, viral, facebook, hrc, gay marriageThe pink-on-red equal sign image created by the Human Rights Campaign to show support for gay marriage as the issue was heard in the Supreme Court earlier this week delivered the LGBT rights group a big social media win.

In an instance of what’s still fun about memes, users created Kosher, not-Kosher, queer-supremicist, Southern comfort, fairy and Martha Stewart spinoffs on the logo. Like a real virus, the logo mutated and spread.

Today, Facebook published its efforts to calculate just how many people changed their profile picture to some version of the image.

“For a long time, when people stood up for a cause and weren’t all physically standing shoulder to shoulder, the size of their impact wasn’t immediately apparent. But today, we can see the spread of an idea online in greater detail than ever before. That’s data well worth finding,” wrote Facebook data scientist Eytan Bakshy on the company’s blog.

A quick rundown of what the company found: More than twice as many users updated their profile photo this Tuesday, March 26, than did the previous Tuesday.

Users closest to 30 years-old showed the greatest increase in photo updates. Just about 3.5 percent of 30 year-olds changed their photos in response to the HRC campaign, Facebook estimates. Those who identify as women on Facebook were slightly more likely than those who identify as men to update their photos.

Using some fancy math, the Facebook team found that response to the HRC campaign was greatest in Washtenaw County, Michigan — the county that surrounds Ann Arbor, Michigan and the University of Michigan. About 6 percent of Facebook users who logged in from this county on Tuesday changed their profile photos in response to the campaign.

College towns, such as Austin, Texas and Ames, Iowa, were among the top responders. And dense cities, such as San Francisco and Washington, D.C. also showed their support for gay marriage.

“Surprisingly, while … population density was correlated with increases in profile updating …, many counties housing large cities like Los Angeles, Chicago, and New York City, showed only modest increases [of] 2.4-2.9% in support,” Bakshy noted.