For the first time, the majority of Americans are using smartphones — even seniors

Don’t look now, but the transition to a mobile-centric computing culture in the U.S. is now certified.

Let’s check some new data points that represent several crossed Rubicons in the march toward Mobile Nation:

For the first time, most Americans in every age group are smartphoners. According to new stats reported today by Nielsen, the age group threshold was crossed in the first quarter. Fifty-one percent of the holdout group — those over the age of 55 — now possess a smartphone, so age is no longer the big factor it was in smartphones’ march to dominance.

Seventy percent of people in the U.S. now own smartphones, Nielsen said. This meshes with another Nielsen study in February, which pegged ownership at 65 percent, and with a Pew Research study in January that found 58 percent ownership.

That growth is being driven by people choosing smartphones when it is time to upgrade from a feature phone or an earlier model smartphone or to buy any mobile phone. Nielsen found that eighty-five percent of handset purchasers in the U.S. are choosing smartphones.

What does this across-the-board wholesale adoption of smartphones mean? For one thing, continued growth for social networks and a shift of social interaction to mobile.

The Nielsen report in February found that 47 percent “of smartphone owners visit social networks every day.” And here’s the relevant Rubicon: eMarketer announced today that, for the first time, “social network usage has made the switch to majority-mobile this year,” with half of all social networking conducted on smartphones in 2014. Another 15 minutes per day on average is spent on social networks through tablets.

eMarketer also reiterated today that “time spent with mobile devices continues to grow much faster than usage of all other media.”

Viewing of video on mobile (33 minutes) is still only a small portion of video viewing across all media, eMarketer said. But the trend line favors — you guessed it — mobile, increasing 50 percent year over year. Time spent with online video and TV is essentially flat.

Given stats like these, it’s odd that some marketers are still discussing how their strategy puts “mobile first.” If there was ever any doubt, mobile is now officially in the driver’s seat.