On March 26, 2013, the marketing team at Human Rights Campaign, the largest organization in the U.S. working toward equality for lesbian, gay, bisexual, transgender and intersex (LGBTI) people, saw some startling numbers: a 600 percent increase in Web traffic, with 700,000 unique visitors in a 12-hour period. Nearly all of those visitors were new to the site.

On Facebook, millions of users — including members of Congress and celebrities such as Beyoncé and Leonardo DiCaprio — had changed their profile images to a red version of the organization’s logo in what Facebook would later call the most successful viral campaign in its history. (The logo is an equal sign and signifies the group’s mission to ensure LGBTI people enjoy the same rights as heterosexuals do.)

Activists outside the U.S. Supreme Court during the campaign for marriage equality (© AP Images)

That day, March 26, the U.S. Supreme Court heard arguments in the case that eventually would make same-sex marriage legal throughout the United States.

The campaign that the Human Rights Campaign mounted in the lead-up to the legal arguments is a study in how to amplify a message and make a big impact. Maureen McCarty, who does marketing for the organization, helped design the successful campaign. Here are McCarty’s tips:

Seize your opportunities

Great campaigns, McCarty said, seize the moment. “We really emphasize, as a marketing team, rapid response,” McCarty said. “During the marriage-equality movement, HRC was frequently first out the door alerting members and supporters about important breaking news.” Being alert to opportunities, she said, means tracking the news closely and responding immediately when a big story breaks, thus positioning your organization as a leader on the topic.

Plan far ahead

Planning for McCarty’s campaign, dubbed “Equality Act,” began two months in advance of the scheduled court arguments. The group used an editorial calendar to outline, day by day, the digital content it would roll out. This buildup got the audience excited about a particular hashtag. McCarty points out that being opportunistic and planning well must work in tandem. “Planning helps us to get ahead of the story, but we also have to adjust to where our audience is. As much as we emphasize an editorial calendar, we need to be flexible if there’s news that day.”

Reach your audience

Online, it can be difficult to reach people where they’re meeting. “HRC is on nearly every social media platform that’s out there,” said McCarty. “We make sure … that we’re putting out content on these platforms that is tailored to their audience and is really responding to what that audience is looking for.”

Keep it real

Authenticity means having a recognizable and credible voice that your audience can rely on. Find experts your audience will trust. “A key to our strategy is bringing in influencers and validators to speak on behalf of our cause and to help reach out to an even broader network of people.”