From a JSTOR Announcement:
Books at JSTOR titles are now available in GOBI3 (Global Online Bibliographic Information), YBP’s acquisition and collection management interface. Libraries can elect to receive new title notifications from GOBI3 or have titles automatically delivered on JSTOR through YBP’s eApproval program. JSTOR’s demand-driven acquisition program will be available through YBP at a later date.
Books at JSTOR features more than 25,000 titles from 57 publishers, including Princeton University Press, The MIT Press, Yale University Press, and many others.
Read the Complete Announcement