Social media prevelance and measurement - opposing forces.

Are these numbers really all that surprising?
According to emarketing.com, 92% of all U.S. companies use social media in their marketing efforts. But based on data from another study conducted by econsultancy.com, just 4% of marketers said their companies were “very effective” at measuring social marketing in 2012. While 47% felt somewhat good at social measurement in 2011, just 38% said the same in 2012. “Nearly half of respondents (47%) feel they or their companies are either not very good at social marketing measurement, or do not measure well at all.”

So that means we have a whole lot of participation and very little measurement. Why is that? When ROI is measured through virtually every aspect of business operations, why does social media get a pass?