The tipping point for mobile is coming fast. So says Ezra Palmer, chief content officer for eMarketer, who discussed the future of media consumption and video ad spending during Ad Age's Digital Conference today.

"Advertisers have been slow to adjust to the rapid uptick of mobile," Mr. Palmer said. "We expect the spending to shift over very shortly."

eMarketer's data shows consumers are watching less TV, but spending more time with video in other places, most notably on their mobile devices.

This year, total daily media time per U.S. consumer is 12 hours and four minutes a day, up seven minutes from last year. According to eMarketer, the uptick in consumption is due to simultaneous device use. (Hours are recorded per device, even if people use more than one device during the same hour.)

Video advertising spending is still imbalanced, according to eMarketer. TV accounts for roughly 90% of the ad money, but only 77% of total time consumers spent with video. Mobile makes up almost 12% of total video watching time, but only gets 3% of total video ad spending.

Other notable figures from eMarketer:

• People are using their mobile devices more—a half hour more than they spend with desktop computers.
• Desktop and laptop time is on the decline. In 2011, the time spent on the two combined was two hours and 33 minutes per day. In 2015, it is two hours and 22 minutes.
• Time spent on mobile is growing sharply, with a total of two hours and 51 minutes a day this year. That number was 48 minutes in 2011, which was twice the time spent in 2010. This figure is starting to plateau.
• The majority of U.S. consumers now regularly use a smartphone, according to February 2015 data.
• Nearly half of the U.S. population now uses a tablet. eMarketer expects modest growth in the future, not nearly as much growth as smartphone usage.
• More than a third of U.S. consumers are using both smartphones and tablets.