If it sometimes seems like Facebook has taken over the world, the most recent report from Nielsen on social media usage in the U.S. provides lots of evidence for that belief.

Americans are spending over 50 billion minutes on Facebook a month, which is more than three times as many minutes as on the second leading website, Yahoo, and over four times as much as on Google.

Women dominate that usage time, accounting for 62 percent of all page views at Facebook, and Millennials (ages 18-34) have the highest concentration of visitors there and at most social media sites among all the age groups.

“Social media’s popularity continues to grow, connecting people with just about everything they watch or buy,” stated the report. “Whether it’s a brand icon inviting consumers to connect with a company on LinkedIn, a news ticker promoting an anchor’s Twitter handle, or an advertisement asking a consumer to “like” a product on Facebook, people are constantly being driven to social media.”

Roughly 80 percent of active internet users visit social media sites and blogs, which now account for 40 percent of their total time online.

Other salient findings include:

• About 40 percent of social media users access this content from their mobile phones.
• 70 percent of active online adult social networkers shop online, which is 12 percent higher than the average Internet user.
• 53 percent of active adult social networkers follow a brand; 32 percent follow a celebrity.
• Tumblr is one of the fastest-growing social media sites, nearly tripling its audience from a year ago.
• Over 31 million people in the U.S. watch video content on social networks and blogs.

Active social media users are much more likely than other Americans to give their opinion on politics and current events, give their opinions on TV shows, spend heavily on music, clothing, shoes and accessories, and  -- go on a date.

These findings complement and expand upon those we reported a few weeks back in our post How Millennials are Changing the World of Media and eCommerce.