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. May 31, 2005 -- 20:09 GMT (13:09 PDT) Loading... Please wait. Topics: Collaboration, Browser, Enterprise Software, Software Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.