Social media moves so fast, it's hard to keep up. Here are the week's top stories in scan-friendly format:

  • Facebook Growth Slows in May
  • GOP Debate Discussed Heavily Online
  • Klout Now Ranks Influence on LinkedIn
  • Instagram Gains 5 Million Users and 100 Million Photos

Facebook Growth Slows in May

Facebook, now at around 700 million users, is the powerhouse in social networking. Month after month, the service has shown amazing growth figures, that is, until this past May. According to Inside Facebook, Facebook's growth was 11.8 million users in May, down from 13.9 million new users in the month of April. In each month during 2010, the service added 20 million new users, on average.

Another interesting note from the latest figures, Facebook lost roughly 6 million users in the United States during May and another 1.5 million in Canada. Are users fleeing Facebook, much like MySpace a few years ago? Not likely -- the service has surging popularity overseas, as Facebook added 1 million new users in places such as Indonesia, the Philippines, India and Mexico.

Why North American users left Facebook is unknown. Considering the numerous security and privacy issues Facebook has suffered, perhaps users decided to forgo the service and delete their accounts. Have you considered dumping Facebook, let's discuss in the comments below!

GOP Debate Discussed Heavily Online

Monday's New Hampshire Republican Presidential Debate was discussed widely online and was a heavily trending topic on social outlets such as Facebook and Twitter. CNN hosted the debate and tweeted the event heavily. CNN's Washington DC Bureau chief actively posted news to Facebook, Twitter and during the event.

By following the hashtag #CNNDebate, watchers online could follow the conversation and gauge sentiment online. At 9PM on Monday night, #CNNDebate was a non-promoted trending topic on Twitter, showing a huge success of CNN's use of the hashtag. Public sentiment was largely negative, with even 'positive' tweets being very sarcastic and demeaning to the Republican participants.

It will be interesting (and entertaining) to see how the 2012 Presidential race unfolds online. With more Americans actively chatting online, the debates should be more present and heated this coming year.

Klout Now Ranks Influence on LinkedIn

Klout is a new website that ranks your influence on social networking sites by providing a score on how much pull you have on various sites. As of yesterday, Facebook and Twitter were the main sites that Klout offered guidance on. Just recently, the social networking rank site added LinkedIn to its portfolio of sites, so users can see their influence on the professional social network using Klout's algorithms.

Klout, at least on Twitter, measures influence by the user's ability to drive action through tweets, re-tweets and more. Regarding Facebook, the service measures your influence by analyzing who you most engage with via likes, comments and more. With the new functionality on LinkedIn, Klout will analyze your interactions and the type and frequency of sharing you do with your LinkedIn Contacts. Simply having a lot of friends on LinkedIn won't help your Klout score, however, having great interactions with your contacts will.

Have you ever heard of Klout? Is your Klout score something you care about? I imagine Klout is a new idea to many and will likely resonate with only a small number of social media users who really want to drive their score up for the sake of doing so.

Instagram Gains 5 Million Users and 100 Million Photos

Photo sharing has long been a popular activity amongst camera phone owners. With 3G data connections and on-board cameras, mobile phones users love to share photos. It used to be that email and MMS were the main ways to share and propagate images, but now a new batch of photo-sharing apps have built a community around mobile photography, led by Instagram on the iPhone and iPod Touch.

The popular service revealed that it now has 5 million users who have shared more than 100 million photos. Adding to this, this last weekend, the service added 100,000 new users and are seeing roughly 860,000 photos posted to the service every day. Like Twitter, Instagram is building popularity by releasing a third-party API that's been embraced by developers and 2,500 applications.

While competitors such as PicPlz are building their audience, Instagram's success is shown clearly in the company's numbers.