Total usage among U.S. adults is up to 72 percent in May 2013 from 67 percent in December 2012, with more older people signing up.
According to Nintendo, the Miiverse experience will be available on other platforms and will include a host of social features.
The second-screen TV companion seeks to blend TV programming with interactive features, including social networks and targeted advertising.
At its E3 presser, Nintendo chose to focus on the Wii U and its games and services, but not so much on specific launch windows or on the next generation of 3DS games.
Nintendo took to the stage at E3 in LA to show off new controllers and a social network for its Wii U console.
Tiny device seeks out social-networking matches in the real world. Now you can find random strangers out at the bar who are into Star Wars furries, too.
Against the backdrop of widespread rioting, David Cameron tells Parliament: "When people are using social media for violence, we need to stop them."
The anticipation continues to build over the star-studded movie based on the origins of Facebook, with the announcement that it'll be the kickoff event at the New York Film Festival.
It's not yet clear whether Armie Hammer will play both of the twin rivals to Facebook founder Mark Zuckerberg with some camera trick help, or whether they've been combined into one character.
A survey of companies' chief information officers reveals that only 10 percent of companies allow unlimited personal social-networking activity on the job and over half block it altogether.