While traditional advertising channels such as TV, radio, and print are fighting an uphill battle against digital media, out-of-home (OOH) advertising has been growing steadily for years. In fact, the format recorded 35 consecutive quarters of growth through 2018, according to the Out of Home Advertising Association of America (OAAA), including a 7.2 percent jump in the final quarter last year, its best performance in more than a decade.

What's behind OOH's ability to buck the prevailing trend for all things new media? A major factor is digital technology — just the thing that's bedeviling the rest of the traditional advertising realm. But that doesn't tell the entire story, says Stephen Freitas, CMO at the OAAA.

"Societal factors are helping drive OOH's success too," he says. "Record miles driven on U.S. roadways and record levels of air travel are placing more people in the OOH space than ever before. For this reason, OOH is largely unaffected by the erosion of audiences through the continued proliferation of media channels."