CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (September 09, 2008)
Total no. participating publishers & societies 2,617
% of non-profit publishers 64%
Total no. participating libraries 1,414
No. journals covered 21,077
No. DOIs registered to date 33,296,311
No. DOIs deposited in previous month 339,214
No. DOIs retrieved (matched references) in previous month 13,966,952
DOI resolutions (end-user clicks) in previous month 18,441,819