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Digital advertising is gaining ground as the medium of choice for political candidates. And now campaigns are making ads that don't just beam messages out. They bring money in. It's all about small donors, as NPR's Peter Overby reports.
PETER OVERBY, BYLINE: Amy McGrath, a Kentucky Democrat, is one of several women veterans running this year. She announced via video back in August 2017.
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AMY MCGRATH: I'm Amy McGrath, and I love our country. I spent 20 years as a U.S. Marine, flew 89 combat missions bombing al-Qaida and the Taliban. I was the first woman Marine to fly in an F-18 in combat.
OVERBY: Mark Nicholas manages McGrath's campaign.
MARK NICHOLAS: It was like a supernova. In a matter of 72 hours, 1.1 million people viewed it on YouTube.
OVERBY: And the campaign raised $300,000 or $400,000. The essential ingredient of viral videos has to be authenticity. Taryn Rosenkranz is CEO of a consulting firm called New Blue Interactive. She described the way candidates have learned to present themselves.
TARYN ROSENKRANZ: I'm a vet. I'm a mom. I'm going through the same things that you are at home. And I think when you can have that kind of emotional appeal to folks, it really makes a huge impact.
OVERBY: A video that goes viral with thousands of views raises money and helps to build a social media network. It also helps candidates swear off money from corporate PACs, a pledge made by 115 candidates now running for the House. Campaigns once relied on rented mailing lists. Now they ask you to click join me and fill in your contact information. That's one part of it.
ROSENKRANZ: We really have found that it's more multiple touches that have been the most effective - mail and television and, you know, email and digital.
OVERBY: These dynamics are a result of Citizens United. That's the 2010 Supreme Court decision that helped to let big donors and corporations spend freely and often anonymously. This really big money flows more on the right. Rosenkranz said Democrats developed their own strategy to fight the Citizens United effect.
ROSENKRANZ: People power grassroots networks that could help them in each congressional race who maybe wouldn't have had access to sort of these big-dollar donors and big, you know, dollar super PACs and whatnot.
OVERBY: So this summer, Amy McGrath had raised $3 million, almost as much as Andy Barr, the Republican she hopes to unseat. Eighty-seven percent of McGrath's money came from people who don't live in Kentucky. They've seen the video or otherwise connected with her, probably online. And even if they can't vote for her, they can vote with their credit cards. Erin Hill is executive director of ActBlue, a digital processing platform used by many Democratic candidates and causes. She said in the 2016 election cycle...
ERIN HILL: Folks used our tools to raise $781 million. And so far in 2017 and 2018, folks have used our tools to raise 1.1 billion.
OVERBY: This year alone, ActBlue has logged more than 4 million donors.
HILL: That's more than the unique donors we saw in all of 2015 and 2016 combined. And we still have the busiest months to go.
OVERBY: Mark Nicholas, Amy McGrath's campaign manager, said they're seeing the results.
NICHOLAS: A million dollars has come in in the last three weeks.
OVERBY: The product of a little campaign in eastern Kentucky that's built a national following. Peter Overby, NPR News, Washington. Transcript provided by NPR, Copyright NPR.