WASHINGTON: While Facebook remains by far the most widely used social media site, the fight for the second spot is becoming ever more intense, new research has found.

The Pew Research Center interviewed 1,802 internet users late last year and established that, as of December, 67% of online US adults used social networking sites and the same percentage said they used Facebook.

Twitter headed a second-tier group, being used by 16% of online adults. This is just ahead of Pinterest on 15% and Instagram on 13%. Further back comes Tumblr on 6%.

The Techcrunch website noted that while Pinterest has "become a magnet for hip urbanites searching for the hottest wedding gowns and apartment decor", Twitter gets all the media attention "since neither presidential campaigns nor Middle Eastern activists are leveraging style catalogs to rearrange their countries' political leadership".

It is the case that there are marked differences in the user profiles of the two sites. While Twitter users divided equally on gender lines, for example, women were five times more likely to use Pinterest – 25% against 5%.

And African-Americans were almost twice as likely as whites to use Twitter (26% vs. 14%), but only half as likely to use Pinterest (8% vs 18%).

In general, Pinterest attracted women, whites, the young, well-educated and those with a higher income.

Like Pinterest, Instagram also over-indexed on women, although not to the same extent. African-Americans (23%) and Hispanics (18%) were much more likely users than whites (11%).

Twitter and Instagram were popular among urban users, recording figures of 20% and 17% respectively, while Pinterest was more likely to attract a rural user (18%).

Tumblr may be significantly less popular than other social networking sites but it was much more prevalent among younger users, with 13% of 18-29 year olds blogging on the site, compared to just 5% of those aged 30-49.

Data sourced from Pew Research Center; additional content by Warc staff