This document summarizes discovery service adoption rates among major library vendors. It reports that EBSCO has the largest number of subscribers to its discovery service (EDS) at 5,612 libraries. OCLC reports 1,717 libraries using WorldCat Local, and Ex Libris has licensed Primo to 1,407 libraries. The document also provides subscriber numbers for ProQuest Summon. It examines themes from user research on discovery services and outlines features and capabilities of EBSCO's EDS product.