More companies are experimenting with providing software as a service (SaaS), and customers are reaping the benefits of their efforts. Customers want their software to be free, both of 'bugs' and of costs, and anything less disappoints them, according to Josh Greenbaum, principle at Enterprise Applications Consulting. There has been a steady transition toward SaaS, since it gives enterprises what they want and need in providing a relatively stable budget item. The cost model is a per-user, per-month fixed fee, which permits firms to predict what its expenses will be. Companies also want more flexibility, and there has been a move toward various kinds of deployment models as well. Mark Clayman, chief information officers with NaviSite, an application management provider, believes the potential for a firm to experiment without making large investments of capital is fueling the SaaS model and its permutations. Since businesses always have small and midsize short-duration projects, the ability to add capacity and applications on an ad hoc basis is very appealing. The industry is seeing a move from strict pricing orthodoxies to experiments that mix deployment and pricing models. This is likely to have a negative impact on major enterprise software firms, however, and the transition will be difficult for them. Salesforce.com is a major provider that is leading the way toward the new models.