Social media can be a powerful online advertising platform, but you have to know what consumers are saying and thinking to reach them with the right message at the right time, according to a majority of 237 senior level marketers surveyed by Web Liquid and RSW/US. Thus one of the main demands of these marketing execs was more and better information about online word-of-mouth.

I'll be honest and tell you that I have no idea if Twitter is worth $8 billion -- the current value assigned to the company after the latest round of investment, which saw Digital Sky Technologies and others pour another $800 million into the microblogging service, according to AllThingsDigital. But I can tell you that the increase in Twitter's valuation over the last two years actually correlates pretty well with the increase in the total number of users and the expanding volume of traffic they produce, globally.

The same qualities that make social media an attractive ad platform recommend it as a communications channel to reach the general public during public health emergencies, according to an article in the New England Journal of Medicine by Dr. Raina M. Merchant, an emergency physician and assistant professor at the University of Pennsylvania's Pearlman School of Medicine.

Earlier this week, Los Angeles experienced the power of social media -- and not in a good way -- after a popular DJ named Kaskade tweeted an invitation to his 92,000 Twitter followers to attend a "block party" to celebrate the opening of a music documentary about the Electric Daisy Carnival, a series of raves (I just totally dated myself), at Hollywood's famous Grauman's Chinese Theater. "Let's see if the magic of social networking will work today," Kaskade tweeted -- and boy howdy, did it ever.

It's hard to know whether Google+ will succeed in attracting the large, stable user base it needs to be a viable social platform. I think even preliminary judgments on that score will have to wait at least three more months, considering it was just launched in late June. However, the latest traffic data from Experian Hitwise suggests the initial, publicity-fueled feeding frenzy surrounding Google+ is subsiding, giving us a better view of its actual appeal in the long term.

As ex-Congressman Anthony Weiner discovered to his detriment, careless posting on social media can have dire, humiliating consequences. But at least he's not alone. It turns out that 18% of Americans say they regret something they sent or posted online, according to the Marist Poll, a national telephone survey of 1,003 adults conducted by the Marist College Institute for Public Opinion in mid-June.

While big mass market social networks like Facebook and Twitter grab the headlines, a new generation of social networks for businesses is quietly expanding alongside. They include companies like Bizzingo, which is launching a business-to-business social network, and Socialcast, which allows businesses to create their own proprietary social networks for employees.

Spectacular, premeditated acts of violence like the bomb attack and mass murder at a political meeting for young people in Norway always leave questions about the motives of the assailant. While no one really expects to make much sense - let alone provide real justification - we do feel compelled to at least try to understand what the perpetrators were thinking. For their part the perpetrators are often eager to explain what "forced" them to commit mass murder. But like so many other things, in recent years the business of publicizing one's crazed beliefs has been transformed by social media.

Social media "incidents," including security breaches and negative publicity, have real financial costs associated with them, according to Symantec, which recently reported the results of its 2011 Social Media Protection Flash Poll, surveying 1,225 executives in 33 countries around the world.

Google+ has clearly been getting a lot of traction, both in terms of new users and publicity, but what's not clear is exactly how many people are using this social thing (which is not a network, thank you very much).