If ever there needed to be a “big bang” validation of the software-as-a-service (SaaS) concept, then SAP’s September 19 unveiling of its Business ByDesign on-demand software for midsize companies surely suffices. Not only is SAP the first major enterprise software player to get serious about SaaS, it is the absolute largest enterprise software player and its move is thus freighted with significance. But there really doesn’t have to be a big-bang validation of SaaS. Many thousands of customers are endorsing the concept every day as they leverage SaaS offerings, and will continue to do so in increasing numbers, with or without the help of traditional enterprise software companies. It is not SAP nor any other huge software company that will drive SaaS. It is the customers who are in the driver’s seat, and SAP is wisely reacting to this fact. And now SAP will have to meet these customers’ expectations—expectations built up by trail-blazing, 100 percent SaaS companies like salesforce.com, NetSuite and Xactly. There’s no doubt that SAP’s on-demand offerings have the potential to provide immense value to the targeted customers—SaaS delivery coupled with SAP functionality packs a powerful punch. But SAP is not about to abandon its on-premise model anytime soon, and its management will be wrestling for some time with such issues as how to keep from cannibalizing its bread-and-butter software licensing revenues and how to successfully support two entirely different delivery models. And along the way, they will learn what 100 percent SaaS companies have known from the start: If you don’t meet the expectations of SaaS customers, they can cut you off in an instant, no questions asked. That’s not something that enterprise software vendors, with their long-term licenses and claws sunk deeply into their customers’ costly IT infrastructures, have traditionally needed to deal with. Still, SAP is doing the smart thing by getting started in SaaS now, when it can be lifted by the rising SaaS tide. In doing so, SAP will add to the tide by increasing the portfolio of software functionality available to customers on demand. SAP’s move doesn’t prove that SaaS is viable. That’s already established. What it really demonstrates is that the traditional enterprise software model is not all that viable for most companies. And for that we welcome SAP to the SaaS world.