54% of marketers had used a third-party blog to get their message out, while 55.4% of influencers had published a sponsored blog post, making it the most popular medium among both groups. But sponsored tweets were not far behind—the poll found they were used by 47.3% of marketers and 51.8% of influencers.
This is one of the questions I get asked the most by marketing and PR professionals! Check out this great graph. Methods Used by US Marketers to Measure Social Media Sponsorships, by Importance, June 2012 (% of respondents)