No licence fees to pay, no hardware to install and no maintenance burden to shoulder. It is no wonder that the concept of software-as-a-service, or Saas, is changing the way many companies purchase and deploy enterprise applications.

Take, for example, Allianz Cornhill, the insurance company. In 2006, it rolled out a CRM system to 350 underwriters and sales staff, so they could track and manage the process of converting sales leads into policies.