Net Zero Buildings, June 2014. (Scroll to page 28)
http://issuu.com/constructionbusinessmedia/docs/1406nzb-r1?e=6596036/8395630#search

"Submetering products and services sales are expected to double by the end of the decade. Commercial tenants seeking to boost efficiency turn to submetering as a way to understand baseline energy use, and to provide verifiable data."