ee Michael Taylor, An altmetric attention advantage for open access books in the humanities and social sciences, Scientometrics, October 00, 0000 (perma.cc link): "Both OA books and chapters have significantly higher use on social networks, higher coverage in the mass media and blogs, and evidence of higher rates of social impact in policy documents. OA chapters have higher rates of coverage on Wikipedia than their non-OA equivalents, and are more likely to be shared on Mendeley." For evidence that the OA advantage also applies to articles whose preprints were OA, see Stylianos Serghiou and John Ioannidis, Altmetric Scores, Citations, and Publication of Studies Posted as Preprints