One screen is no longer enough for many adults. This group is most comfortable when multi-tasking with two screens simultaneously. According to a recent report by the research firm CivicScience, 48 percent of U.S. adults say that they are engaging with a second screen (smartphone, tablet or laptop) at the same time they are watching a favorite television show or movie on a standard TV. This compares with 38 percent of adults who say that their devices “are put away” while they watch TV, according to the CivicScience report.

The “other” 13 percent either don’t watch TV, don’t own a smartphone, tablet or laptop, or they watch video only on mobile devices, the report found.

“While attention appears to be relatively high, when the responses are simplified into those who are engaged with the TV show on the primary screen versus those who are distracted, it becomes clear that almost half of adult respondents (48 percent) are distracted by their second screen,” CivicScience reported. “The percentage of those distracted by unrelated content on apps has increased steadily since 2015.”

As a result of this trend, eMarketer has forecast that 180.8 million U.S. adults will be two-screen viewers in 2019—meaning that 70.1 percent of the adult population will use a computer or mobile device to browse online while watching either digital video or traditional TV.

“The increasing simultaneous users of internet and TV—an audience that we estimate has grown by 32.3 million in the past five years—could be an opportunity for marketers to reach subscription video-on-demand (VOD) users who don’t see ads while watching video,” eMarketer said in its analysis of the report’s findings. “But finding out where to target this audience on their second screens won’t be easy, as the majority of viewers don’t engage in content related to what they are watching on TV.”

According to CivicScience’s findings, of the 48 percent who browse online while watching television content, 23 percent are viewing mobile apps, games or other content that isn’t related to what they are watching on their main screen. Eighteen percent either text or check email, and only 7 percent said they view or engage with content related to the program they’re watching, the research firm said.