Apple's looming acquisition of Shazam has prompted one of the company's senior executives to bounce.

Greg Glenday, chief revenue officer at Shazam, is leaving to join Adspace Networks as the company's CEO. He assumes responsibilities that had been handled by Jim Sullivan, a board member who was acting CEO, and Peter Kreiger, chief operating officer, since CEO Dominick Porco left in 2015. Kreiger will now report to Glenday.

Adspace has some 5,000 digital displays in malls throughout the country.

"Shazam is getting acquired by Apple and they have a different business model," Glenday says. Advertising isn't a huge part of Apple's business, so he didn't see a long-term place place for himself at the company, he says.

Out-of-home might be the most underappreciated advertising format, but it is sizeable and growing. Spending on out-of-home ads reached nearly $10 billion in 2017, according to the Interactive Advertising Bureau's annual revenue report.

That puts it nearly in the same ballpark as digital video, which saw roughly $12 billion in 2017, the IAB says. The difference, Glenday says, is that digital media is under pressure to prove its worth. "In digital, everything has to be viewable and fraud-free," he says. "TV viewership is down but the upfronts are up and that is because there is a flight toward quality."

(Another difference, however, lies in the rate of growth: Digital video spending rose 33 percent last year, compared with 4 percent for out-of-home.)

Out-of-home business is riding recent tech advancements that enable better measurement and creative executions. Advertisers can, for example, see how many people visited a store or made a purchase after walking past an out-of-home ad. The format can also be purchased programmatically.

Glenday argues that out-of-home advertising has opportunities in areas such as augmented reality and tech-fueled creativity in general, as seen in a digital poster to make a woman's hair move when a train passed by.

"Advertising doesn't have to be something you have to sit through as punishment," he says. "Out-of-home is not in the way, whether it is static or video, I think there is an opportunity of interactive advertising where you have a curious consumer that you're not stopping them from what they want to do."

Before Shazam, Glenday held posts at companies including iHeartMedia and Undertone.