Ruby Karp may have written,"I'm 13 and None of My Friends Use Facebook," but according to a new study, Mark Zuckerberg's social network remains the platform of choice for adults, with 71 percent using the website in the U.S.
A new study by the Pew Research Center found that 73 percent of online adults are now a member of a social network, and Facebook remains the dominant platform. Its survey of 6,010 U.S. adults over the age of 18 found a slight increase in Facebook users in 2013, up from 67 percent in 2012.
However, the Pew research also found that more adults used professional networking site LinkedIn and photo pin-up site Pinterest than Twitter. Some 22 percent of those surveyed said they were on LinkedIn, and 21 percent had Pinterest accounts - but only 18 percent were on Twitter. This marks a change from 2012, when more adults used Twitter (16 percent) than Pinterest (15 percent).
"While Facebook is popular across a diverse mix of demographic groups, other sites have developed their own unique demographic user profiles," senior researcher Aaron Smith and research assistant Maeve Duggan wrote in the report.
(Read more: Facebook monthly active users )
"For example, Pinterest holds particular appeal to female users (women are four times as likely as men to be Pinterest users), and LinkedIn is especially popular among college graduates and internet users in higher income households."
But there are concerns of a growing disillusionment among teenagers with Facebook, as Twitter and Instagram (which is owned by Facebook) grow in popularity. When it reported earnings in October, Facebook CFO David Ebersman admitted that the daily activity among younger teens has declined.
The Pew Survey noted that Twitter and Instagram were more appealing to younger adults, urban dwellers, and non-whites, and that there was a "substantial overlap" between Twitter and Instagram users.
(Read more: Who's viewing your Instagram, and profiting from it? )
This mirrors other recent findings, such as those by U.S.investment bank Piper Jaffray, which conducted its semi-annual "Taking Stock With Teens" project back in October.
It found that Twitter was fast becoming the most important social media network among younger users, and was "eclipsing Facebook, followed closely by Instagram." Thepopularity of Facebook was waning among teens, the bank said, with 23 percent citing it as the most important, down from 33 percent six months ago and 42 percent a year ago.
Indeed, in her August op-ed on news site Mashable, Karp wrote: "Part of the reason Facebook is losing my generation's attention is the fact that there are other networks now. When I was 10, I wasn't old enough to have a Facebook. But a magical thing called Instagram had just come out."
Professor Daniel Miller, who is working on University College London's Social Networking Sites and Social Science Research Project, found a similar trend.
He wrote that among a small survey of 16 to 18 year olds,"Facebook is not just falling, it is basically dead, finished, kaput, over," and that many users will only stay on the website as a "mode of family interaction because their parents and even grandparents are starting to see it as almost an obligation to keep in touch through Facebook."
Still, Gregor Galant, the CEO of Muck Rack told CNBC in October: "I think Facebook's going to be around for a very long time, not because their current product can last the test of time but because they're unusually adept at evolving."
Indeed, the Pew Survey stressed that Facebook is still the platform that engages its users the best.
"In addition to being the most commonly used social networking platform of the five we measured, Facebook also has high levels of engagement among its users," the report noted. "63 percent of Facebook users visit the site at least once a day, with 40 percent doing so multiple times throughout the day."