It's hard to miss: the term Software as a Service (SaaS) is everywhere, garnering headlines in the technology press, leading to hot IPO's raved about in the financial press, and generally being described as the future of software technology. With this kind of press, virtually every major software vendor is touting some version of SaaS, leading to confusion about the solution model and its advantages. This paper attempts to clear this haze by clearly defining the term, and describing the short-term and long-term benefits of the solution model and its variants.