Sarah Evans, author of social media and PR blog “Commentz” regularly compiles interesting stats and facts about social media. She recently shared her most relevant ones with Ad Age. Some can be useful to healthcare marketers.

1. “In early March, Google removed from its Android Market more than 60 applications carrying malicious software. Some of the malware was designed to reveal the user’s private information to a third party, replicate itself on other devices, destroy user data or even impersonate the device owner.”

2. “Groupon is on track to bring in between $3 billion and $4 billion in revenue this year alone. Facebook’s 2010 sales were reported to be only around $2 billion in its sixth year of existence.”

3. “A study of 24,000 consumers across the 16 largest countries found that those who are most connected, living on the cutting edge of social media tend to be more ‘prosocial’ than average, being more likely to do volunteer work, offer their seats in crowded places, lend possessions to others and give directions.”

4. “99 percent of Android devices are vulnerable to password theft.”

5. “Recent estimates put less than 10% of the population using Twitter, far less than other social sites.”

6. “More than 3.34 million mentions were recorded over a one-month period of people making social asks.”

7. “David Poltrack, CBS Corp., announced that, based on a new research study, ‘age and sex don’t matter when it comes to increasing TV ad effectiveness.'”

8. “An average of 40 percent of the traffic to the top 25 news sites comes from outside referrals, the study found, with Google Search and, to a lesser extent, Google News the single biggest traffic driver.”

9. “Almost one-in-four South Africans use social media as a tool to look for work, but are concerned about the potential career fallout from personal content on social networking sites.”

10. “The percentage of US parents who allow their children between ages 10 and 12 to use Facebook or MySpace more than doubled from 8 percent a year ago to 17 percent now.”

11. “33% of Facebook posting is mobile.”

12. “Fully 69% of visitors to news.google.com ended up 3 places: nytimes.com (14.6%), cnn.com (14.4%) and abcnews.go.com (14.0%).”

13. “85% of media websites now use online video to cover news.”

14. “”Social media advertising spending will increase from $2.1 billion in 2010 to $8.3 billion by 2015.”

15. “Facebook is approaching 700 million users and Google handles over 11 billion queries per month. World-wide there are over 5 billion mobile subscribers (9 out of 10 in the U.S.) and every two days there is more information created than between the dawn of civilization and 2003.”

16. “Twitter reported that the network saw more than 4,000 tweets per second (TPS) at the beginning and end of Obama’s speech [re: death of Osama Bin Laden]”

17. “65% of all social media related to the royal wedding has come from the U.S. in the past month [April]. The U.K. has been responsible for just 20%.”

18. Re: the Royal Wedding: “911,000 wedding-related tweets were tracked in the past 30 days. That’s about 30,000 per day and accounts for 71% of all social media.”

19. “According to NPR’s internal usage data covering January 1 through mid-April, users who request audio — maybe a station stream, a national newscast, or NPR Music content — view twice as many pages as those who only read the apps’ content. On average, audio streamers rack up 4.2 pageviews per visit versus 2.4 for the text-only crowd.”

20. “Twitter penetration rates in Canada are among the highest in the world, according to new data from online tracking firm comScore Inc., which suggests that nearly one in five Canadian Internet users over the age of 15 regularly visit Twitter.”

21. “Traffic from social media has highest bounce rate. […] If you’re looking for ‘hyper-engaged’ readers, those that click through five or more pages on your site, forget the guy who came from Twitter. A link from another content site is three times more likely to be engaged, and someone coming in from search, is also above average.”

22. “”Digital services accounted for an estimated $8.5 billion (28%) of the $30.4 billion in 2010 U.S. revenue generated by the 900-plus advertising and marketing-services agencies that Ad Age analyzed.”

23. “Total Facebook spent on lobbying, Q1 2010: $41,390. Total Facebook spent on lobbying, Q1 2011: $230,000”

24. “Nearly seven in 10 tablet owners reported spending at least 1 hour per day using the device, including 38% who spent over 2 hours on it. And while just 28% consider it their primary computer, 77% are spending less time on desktop or laptop PCs since they got a tablet.”

25. “According to a Network Solutions survey, the use of social media among SMBs has grown over the years, rising from 12 percent in 2009, to 24 percent in 2010 to 31 percent currently.”