Software as a service (SaaS) has gone beyond the realm of rogue deployments, and CRM software, most notably Salesforce.com, has led the way through the enterprise front door. IT pros have learned plenty about the pros and cons of on-demand CRM. Among the lingering concerns: Can you make Salesforce.com and other on-demand CRM apps play nicely with your ERP and other core systems? How much work and what arrangements will this integration require? Results still vary.

Calvin Do, CIO of colour equipment manufacturer EFI, knows firsthand the limits of SaaS integration to enterprise processes. For example, he's discovered that SaaS providers don't typically support single sign-on, an obvious enterprise need. And they often don't support APIs of other enterprise applications, at least not out of the box. For example, connecting Salesforce.com to Oracle and SAP applications requires buying additional connector software or creating your own connectors via Web services. The limited cross-vendor integration is why Do initially restricted his SaaS deployments of Salesforce.com and talent management application SuccessFactors to department-level applications. (He later added an enterprise-wide deployment.) In the department-level applications, integration is handled at the data-exchange level and via simple API calls to trigger, for example, a data upload and the related process.

The trick: Don't let on-demand CRM's advantages blind you. Enterprises must carefully consider the scope of their on-demand CRM goals and whether potential software has the integration capabilities to fit with the larger software portfolio.

"You can't simply outsource CRM. It will ultimately need to integrate into your people, processes and technology," says Isher Kaila, research director for CRM at Gartner. "Only a minority of implementations out there have got this [trade-off] right," he adds.