CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (January 11, 2008)
Total no. participating publishers & societies 2,494
% of non-profit publishers 64%
Total no. participating libraries 1,341
No. journals covered 19,712
No. DOIs registered to date 30,313,483
No. DOIs deposited in previous month 405,816
No. DOIs retrieved (matched references) in previous month 5,595,122
DOI resolutions (end-user clicks) in previous month 13,853,828