LinkedIn, Facebook, Twitter, blogs and YouTube were, as you might expect, rated highest. However, the degree to which each was rated as effective, and how it is being used, varied significantly with company size and across the industry groups surveyed. Concerning other sites, Wikipedia showed some value as a brand and awareness tool, but Reddit, Digg, Foursquare, StumbleUpon, and others seem to be having little impact in B2B.
Overall, B2B companies have broadened their use of social media when compared to results from our survey last spring. Their #1 use for social media continues to be for brand and awareness, i.e., one-way, outward communication. But B2B firms are finding social media to be increasingly effective for listening/gaining insight, generating leads, creating preference, and building customer satisfaction and loyalty.
The survey showed social site use patterns to vary with company size. 
As a group, firms less than $100M in annual revenue rated LinkedIn to be the most effective social site, especially as a tool for listening/insight and as a lead generator. Blogs were rated next most effective by this group and rated highest in effectiveness for customer satisfaction and loyalty. Twitter and Facebook follow closely. YouTube was rated to be effective, especially for awareness building, but scored significantly lower than the others.
Large firms exhibited a very different profile. 
Twitter received the highest scores and was rated as most effective for brand awareness, listening to customers and the market, and customer satisfaction/loyalty. Facebook, LinkedIn, and YouTube formed a second tier. YouTube was rated much higher in effectiveness by large firms than by small firms.
The responses were also analyzed by industry and business type, including computer H/W, S/W, biotech, telecom, other manufacturing, services, agency, consultants, and other. While much of the variance in scores correlated with company size, there were some patterns of difference in the use and effectiveness ratings across these groups.
For example, agencies and consultants rated LinkedIn as the most effective site by a wide margin, followed by blogs, with Twitter and Facebook significantly lower.
For corporate or client side respondents, small firms tended to rank Facebook higher and LinkedIn and Twitter lower. As firm size increased, ratings for LinkedIn and blogs dropped, and scores for Twitter and Facebook increased. Firms with more than $1B in sales rated Twitter and Facebook about the same, and much higher than other sites.
Implication: Your social media strategy should be developed based upon the specific needs of your company and market. However, the basic patterns found in this study, even simply using company size, offer a guide for where and how to expend your social media efforts for the highest effectiveness. If you have questions or for more detail, please feel free to comment. And check in every 3-6 months, as social media is changing faster than the annual planning cycle typical of B2B companies.
GLG 032411
