While in the past vendors of subscription-based software provided both data and infrastructure, the newest versions provide access through someone else's infrastructure. However, the on-demand model is becoming popular again, and IDC predicts annual rises in global sales of hosted software each year of 26% for the next two years. Halsey Minor, CEO for Web services provider Grand Central Communications and founder of CNET Networks and other companies, as well as Marc Benioff, CEO of Salesforce.com, are quite sure that pay-per-use services will take off like a rocket. With the new model, the data user acquires software and installs it on owned machines, and the overall investment of larger companies will be large. Smaller users will probably use what is given by the maker. A license is purchased, rather than a product, and the license paid for is perpetual. However, that model is also changing, says a recent survey, which shows that 33% of vendors now sell subscriptions, and 67% sell perpetual license. Payment is made up-front. Among topics covered are problems with the present model how software works under the new models, and the reason for the spike in subscription software at the present time. Technical and economic factors have prompted the paradigm change, including the cost of software development, rugged competition in the market, common standards, scalability, easy integration, and available alternatives. Also instrumental in the trend are open source, more bandwidth, and Web services.