If you'd like to know how many people have read a particular article, the number of views is displayed on the submission's Editing page beside the Galley file in question. For more detailed statistics on the site usage, I'd suggest installing a server log file analysis package such as Webalizer.
For statistics on the journal itself (i.e. acceptance rates etc.) see Statistics & Reports in the Journal Manager's interface.
Open Journal Systems Team
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July 11 - 13, 2007, Vancouver, BC, Canada