Facebook has apparently become an even bigger time suck for Americans.
A study released Monday  by Nielsen revealed that Internet users in the U.S. spent a total of 53 billion minutes on Facebook in May 2011 -- more than any other website.
That's up 6 percent from 50.6 billion minutes a year earlier.
Coming in at No. 2 was Blogger (723.8 million minutes), followed by Tumblr (623.5 million), which nearly tripled its audience from a year ago; Twitter (565.2 million;) and LinkedIn (325.7 million).
Overall, Nielsen found that Americans spend 22.5 percent of their Internet time using social media, compared to 9.8 percent for online games and 7.6 percent for e-mail.
Facebook was by far the most popular social media site, with 70 percent of Americans who use the Internet on the site.
Nielsen's study, called State of the Media: The Social Media Report, examined "trends and consumption patterns across social media platforms in the U.S. and other major markets, exploring the rising influence of social media on consumer behavior."
-- Nearly 40 percent of people who use social media access the content from their cell phones.
-- People over the age of 55 are the major drivers of social networking growth.
-- Seventy percent of active online adult social networkers shop online, which is 12 percent more likely than the average adult Internet user.