Primary Research Group has published Library Use of the Mega Internet Sites, 2011-12 Edition, ISBN 1-57440-177-7. 

The report presents data from more than 100 corporate, legal, college, governement, and public libraries about their use of Google, Yahoo!, YouTube, Wikipedia, Amazon, Facebook, Twitter, and other mega internet sites. The report shows how useful various sites are to the professional efforts of librarians and what librarians are achieving in using the sites.

Just a few of the many findings from this 154-page report are:

• 29% of the libraries in the sample were currently working with search engines or other organizations to digitize elements of their collections and make them available over the internet.
• 60% of public libraries in the sample have held workshops in Facebook use; 17.39% of college libraries, 10.53% of law/corporate libraries, and 14.29% of government agency/department libraries have done so.
• Google Books was found useful by 21.90% and highly useful by 16.19% of the sample. Another 35.24% of libraries found it occasionally useful.
• Wikipedia was most popular among librarians working in technical services and cataloging; 71.43% of these librarians found it highly useful.
• 41% of the libraries sampled had a Twitter account.

To view a table of contents and an excepert, or to order, visit the publication's page here.