How the U.S. presidential campaigns are targeting digital ads by zip code

If you want to know anything about what digital ads the Kamala Harris and Donald Trump presidential campaigns are running, and in what locales they're running which ads, Penn's Andrew Arengeis your guy. He has, after all, watched more than 15,000 locally targeted digital ads across the two campaigns-and that doesn't even include ones running statewide or nationwide.

Arenge, director of operations for the Penn Program on Opinion Research and Election Studies, created a dashboard showing targeted digital ad spending from the Biden and then Harris campaignand one for the Trump campaign. Users can see the states and individual zip codes where the campaigns have targeted ads, how much money the campaigns have spent, and which topics are aimed at which zip codes, such as the economy, health care, democracy, immigration, crime, abortion, and Project 2025.

"I've long been convinced that this data is a good leading indicator of where the candidates are putting their resources and how are they thinking about where their voters live," Arenge says. "Folks just haven't taken the time to understand it, and to try and find meaningful insights."

He was clued in earlier than most that North Carolina, which the Republican candidate has carried the past three presidential elections, is now in play. He noticed that the Trump campaign began targeting zip codes in Maine's 2nd Congressional District, which Trump won in 2020 and 2016, and that the former president started running an ad about fracking in western Pennsylvania. He saw that in mid-September, the Harris campaign began running ads in heavily Arab American neighborhoods in Michigan.

Running ads on Google, Snapchat, Twitter, and Meta, which owns Facebook and Instagram, gives campaigns the ability "to target much more granularly" than with TV ads, Arenge says. But, he says, overall, digital ad spending remains much lower than TV spending. He has found that Democrats are spending significantly more on digital ads than Republicans and are doing more specific geotargeting.

"It struck me that we are all blinded by our own experience. I know what ads I've seen, partially because I pay really close attention to it, but I have no idea what ads you've seen," Arenge says.

He created a third dashboardwith daily spending on Meta by each campaign. He noticed that compared to 2020, spending is down on Meta ads across platforms but up on Google, and that spending on Meta ads from the Harris campaign spiked after the debate.

Although Arenge launched the dashboards this spring, they are an evolution of a five-year project. In 2019, he noticed that in the wake of the Facebook-Cambridge Analytica data scandal, some tech companies had launched data transparency platforms. He has been downloading Meta's daily spending report every day since, and over time has also been paying attention to what other platforms were releasing.

In the 2020 election, he noticed the Biden campaign was targeting different messages at different communities. For example, a video running in some Pennsylvania zip codes focused on his religiosity in broad terms, whereas one in other zip codes highlighted his Catholicism.

But Arenge thought the data was not presented in a helpful manner, and "it struck me that somebody should do something to make it easier to understand what messages they are running where and how much they are spending in different places," he says.

"I care about everything and am really fascinated by all the geographies," he says, "but the average person only cares about where they live."

His dashboard has gone through multiple iterations and benefitted from user feedback, he says. He captures the data on targeted ads, watches each ad, quickly determines the main topic of each, and puts the data through a script that codes spending by zip code.

"The ads that everybody talks about generally aren't always the ads that they're putting money behind," Arenge says, noting that there's a fascinating dichotomy between the ads journalists tweet about and the highest spends.

Arenge says his goal is to keep the dashboards as updated as possible through the election. "There's more I want to do with it all that's more academically oriented, paper-wise," he says, "but as I like to joke, that's a 2025 problem, because there are only so many hours in a day."