Understand on-demand Summary: Adam Gross of Salesforce.com says it's important to keep two concepts in mind: 'single tenant' and 'multi-tenant'. He says a multi-tenant approach facilitates upgrades, maintenance and expansion and affects e-mail, CRM and ERP applications. April 26, 2006 -- 00:04 GMT (17:04 PDT) Loading... Please wait. Topics: Software, Collaboration, Enterprise Software Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.