When Alex Ewing was a kid growing up in Purcell, Oklahoma, he knew how close he was to home based on which billboards he could see out the car window. Now, as the CEO of OneScreen.ai, he’s helping startups like fintech Ramp and technical recruiter Karat advertise on billboards and beyond.

“I think billboards are cool and help bring creativity back into marketing,” Ewing told TechCrunch. “They are like canvases for marketers in a way a digital screen isn’t.”

Ewing joined Boston-based OneScreen last year. The company acts as a software-enabled middleman in between startups and out-of-home (OOH) advertising slots like billboards, subway ads and others. OneScreen helps startups find the right placement for their ads based on the potential customers companies want to reach paired with the demographic and historical data on the platform. The company also uses anonymized location data to help companies track how successful their campaigns are, too.

OneScreen has raised $4.7 million from investors including Asymmetric Capital Partners, Techstars and Impellent Ventures, among others. The company is currently profitable and tripled its revenue last year.

Billboards and other types of OOH marketing are becoming increasingly en vogue, especially for startups, Ewing said. OOH advertising spend in the U.S. is expected to reach $9.3 billion this year, according to Statista, and predicted to reach nearly $12 billion by 2029.

But why would a B2B company like Ramp, want to advertise in a classic consumer manner like the exterior of city busses or inside subway cars?

Ewing said that companies are looking to turn their attention back to OOH advertising strategies after years of being focused on digital marketing. He added that regulations around privacy and targeted ads, and the ability for people to block digital ads, have made online advertising strategies less successful for many.

“B2B, B2C, companies everywhere from Series A, Series B, [companies that are] really well funded or publicly traded have said, ‘we can’t invest what we’ve been investing in digital anymore, the ROI isn’t there,’” Ewing said. “It continues to get more and more expensive and it’s getting less and less effective.”

What this kind of advertising creates is brand recognition which is more effective for B2B companies than people may realize even if the majority of people who see the ad aren’t likely to become customers.

In February, Hila Perl, the director of strategic communications at Papaya Global, told TechCrunch that B2B HR startup Papaya was buying a $7 million Super Bowl ad for that exact reason.

“It’s not a lead generation move,” Perl said about the company’s ad purchase. “It’s not so we can sell more. Obviously, yes we want to see a very direct ROI but we all understand this is a brand building or a brand awareness play, it’s not a lead generation play. In my mind it’s always a marathon rather than a sprint.”

While OneScreen can’t control who sees an OOH ad, Ewing said his company can still help companies reach a targeted audience. B2B companies can give OneScreen a list of target customer companies and OneScreen’s tech will develop a strategy for them that includes advertising slots near their target companies’ headquarters or where their employees might be commuting in and out from. It uses anonymized cell phone tracking data to see how people reacted to the ad through metrics like website traffic from people that passed the ad compared to those that didn’t.

The downside is that, the ROI on OOH ads can’t be tracked as easily as connecting the dots between someone clicking on a digital ad and then purchasing online shortly after. But the hope is that seeing a New York MTA bus wrapped in a Ramp ad will be more effective than a cold sales pitch email.

“There is nothing more powerful than seeing a company and brand in the real world,” Ewing said. “If you get that in front of the right people, that can be a powerful way to soften the beachhead for inbound or to simply just drive leads.”