In today’s economic climate, marketers are trying to do more with less by making more efficient media buys. The most cost efficient, and often most trusted form of media is word of mouth. Senior Forrester Research Analyst Jeremiah Owyang called word of mouth the holy grail of marketing.

Organizations like hospitals rely heavily on word of mouth to remain top of mind for patients choosing a health care institution for their treatment. Lee Aase from the Mayo Clinic presented at the Community 2.0 Conference in San Francisco on how the Mayo Clinic is using social media to share their message with the existing community and extend the reputation built over many decades through word of mouth.

As millions of new users continue to join and use Twitter, retweets are quickly becoming the most effective way to socially endorse a brand or comment. A retweet is repeating someone else’s quote or tweet on Twitter. Owyang’s blog post called retweets the core essence of viral content spreading, as the content of a retweet was so valuable and important to that user that he or she was willing to share it with their network. And Forrester research indicates that Twitter users are brand sensitive.

Retweets are one way to make measuring and monitoring word of mouth more tangible and accurate. Repeets.com, a new site launched this week by our own Adam Coomes, tracks the hottest and most retweeted tweets of the day, week and month, providing a snapshot view of the most shared tweets. Mesiab Labs has launched www.retweet.com, an online petition users can sign to endorse retweets with the hope of creating enough support that Twitter will make an official Retweet button.

The chart below shows the steady rise of retweet or RT references online. Check out the spike from April to May 2009. How is your brand using and measuring retweets?

We received a lot of feedback on yesterday’s Social Radar Top 50 (March 2009) post and wanted to provide some additional thoughts. A brand is a promise; a collective of perceptions. Our Social Radar Top 50 Social Brands list was calculated based on overall conversation volume, including millions of blog posts, news feeds, forums, social networks and Twitter posts. To determine our top 50 brands, we aggregated a massive list of thousands of the words and brands on the web during March 2009, then conducted further analysis to rank the results. Our list measures the number of unique individuals or sources that posted content about each brand during March 2009 rather than the overall number of mentions, which would be more heavily influenced by big fans who post frequently about a specific brand.

We did not base our list on number of searches, which you could easily do using Google Trends. We measured conversations and web chatter. If you’re a brand manager, do you want to know who’s searching for your brand? Absolutely. Do you also want to know how many people are talking about your product online? Absolutely. If you need to do some home repair, say, fix your cabinets, you’ll probably start with a Google search. But are you going to blog about your experience? Probably not unless it’s extraordinarily good or bad.

We also did not base our list on revenues. The Business Week / Interbrand list of top global brands for 2008 is evaluated based on how much the brand is likely to earn for the company in the future. Interbrand uses a combination of analysts’ projections, company financial documents, and its own qualitative and quantitative analysis to arrive at a net present value of those earnings.

Coke and McDonald’s are both on Interbrand’s top 10 list, but both brands were outside of our top 50. Social media doesn’t necessarily correlate to market share. How often are you blogging about the Coke you bought from the vending machine? On the other hand, technology is always advancing and people often chat or post about new updates and features. Check out the chart below comparing chatter for Coke, McDonald’s and iPhone throughout March 2009.

There are many reasons why products have large market share. Microsoft products are still predominately used in many corporate settings, and in some cases employees at those corporations might prefer to use Apple products but aren’t given the choice. Apple’s market share has increased dramatically in the last few years. Who knows if Apple will surpass Microsoft in the future, but they are generating more buzz than Microsoft on the web thanks to passionate Mac and iPhone users.

Social media is evolving. Companies are just now beginning to hire social media strategists to interact with consumers. Social media is still a low priority for many large corporations because of lack of perceived ROI. So they are still experimenting with ways to become part of the conversation. Companies that can create real-time interaction and involvement with their customers will be best prepared to succeed in the new media world. How can companies capitalize on or increase online buzz? Will it translate to increased revenue in the future?