SalesForce provides CRM software, but they provide it in a SaaS(Software as a Service) business model.
They’ve been around for years, but now with their web based interface going the true Web 2.0 route and integration and partnerships with companies like Google(Gmail) they’ve gained a lot of ground with their good strategic decisions.
Easy-to-use Web-based CRM solution for sales, service, marketing, and call center operations that streamlines customer relationship management and boosts customer satisfaction. Organizations can enjoy unparalleled productivity, revenue growth, and business intelligence with Salesforce CRM
Apparently SalesForce have about 50 000 enterprise customers with approximately 1.5 million individual subscribers logging into their systems. This is a large client base, and according to the latest TechCrunch post by Eric Schonfeld, they apparently only run on a mere 1000 servers, which is much better than other SaaS providers.