Defending Main Street, a super PAC backing Maine Sen. Susan Collins, spent nearly $25,000 on digital attack ads against her Democratic rival, Troy Jackson — in Portland, Oregon, rather than Portland, Maine. Like all super PACs, the group may raise unlimited sums to support a candidate, but it must operate independently of that candidate's campaign.

Collins has represented Maine in the Senate since 1997 and is often viewed as the epitome of the state. Like Jackson, she grew up in the state's northern tip. Her family ran a lumber business for generations in Caribou, and Mainers know her as someone from "the County" rather than a career politician. During the Barack Obama era, her bloc of crucial swing voters included Pennsylvania's Arlen Specter and fellow Mainer Olympia Snowe; she is the last of those Republican moderates still standing, giving Maine an outsize national footprint.

So when a political attack ad ran in Portland last week, it would have been safe to assume the city in question was in Maine. Instead, the super PAC backing Collins picked the wrong one.

Defending Main Street spent nearly $25,000 on digital placements for "So Many Taxes," a 30-second ad attacking Jackson, running it across hundreds of zip codes in Oregon and Washington State from Oct. 8 to Oct. 11, according to Google's Ads Transparency Center. Zip-code targeting is how digital campaigns keep their messaging inside a particular state's electorate — which means the misplaced spots were served to viewers with no vote in the Maine contest. The error came to light when an Oregon X user reported seeing five anti-Jackson ads in a single day.

"I choose to believe they mixed up Portlands," the user wrote.

The same ad ran as intended on broadcast TV in the Portland, Maine market, drawing about 675,000 impressions over the same four days, according to AdImpact data cited by MS NOW.

Defending Main Street told Newsweek that its media vendor mistakenly placed the digital ads in the Oregon market, and Newsweek reported that the targeting was fixed by Monday afternoon. Sarah Chamberlain, president and CEO of the affiliated Republican Main Street Partnership, told NBC News she was furious with the ad buyer, Cross Screen Media, which she said refunded the money. "I would never run an ad in Portland, Oregon, for Susan Collins," she said.

Jackson's campaign was quick to weigh in on the mishap. "Susan Collins's allies are so out of touch with Maine, they can't even find it on a map," campaign spokesperson Dan Gottlieb told Fortune. "Good luck convincing Mainers you know what's best for them when you don't know which Portland they live in."

Defending Main Street and the Collins campaign did not respond to Fortune's requests for comment.

A $26.8 billion mix-up

The super PAC got its money back, but the mistake mirrors a problem that costs corporate advertisers billions. The Association of National Advertisers estimates that $26.8 billion in global ad spending is lost each year to middlemen's fees, fake traffic, unseen ads, and low-quality sites — up from $20 billion in 2023. That is more than double the $11.6 billion AdImpact projects will spent on political ads across the entire 2026 election cycle.

Much of that waste comes from ads running in places advertisers never chose. In the ANA's 2023 study, the average campaign ran on 44,000 websites, even though a few hundred sites would have reached most of the intended audience — and participants had not approved about 38,000 of those sites. In the group's latest benchmark, more than a third of automated ad spending still went to ads that failed basic quality standards.

AdImpact has projected $384 million in ad spending on the Maine Senate race, nearly double the roughly $200 million spent when Collins last ran in 2020. In this race alone, Republicans are outspending Democrats but getting less for each dollar: from July 26 to mid-September, Republicans spent $82.1 million on TV ads in the race to Democrats' $55.5 million, according to AdImpact data. Super PACs pay full price for TV ads, while candidates' campaigns receive discounted rates — a gap that makes any wasted airing costlier for outside groups.

Location targeting — the tool that sent Defending Main Street's ad to Oregon — can backfire. A 2019 analysis by data firm Location Sciences of 500 million location-targeted ads found that 29% were delivered outside the area the advertiser had paid to reach.

In 2017, the New York Times showed JPMorgan Chase one of its own ads on a site called Hillary 4 Prison. The bank found that its ads had appeared on about 400,000 websites in a single month, but only 3% of them produced any activity beyond someone seeing the ad. Chase trimmed its list to about 5,000 preapproved sites and saw little change in the cost or visibility of its ads, its chief marketing officer said.

That same year, after activists flagged Uber's ads on Breitbart, the company began cutting its online ad spending. Kevin Frisch, Uber's former head of performance marketing, later said the company turned off $100 million of its $150 million annual online ad budget for riders and saw no change in app installs. He blamed ad networks that took credit for sign-ups that would have happened anyway.

This story was originally featured on Fortune.com.