Both Microsoft and Google improved their service agreements for online offerings last month, giving IT pros more incentive to move their email and documents to the cloud. 

Web-based services, such as Google Apps and Microsoft Business Productivity Online Suite (BPOS), appeal to cost-sensitive businesses that want to ease the burden of installing and supporting Exchange Server, SharePoint Server, Office and other products.

Source: http://searchwinit.techtarget.com/news/2240031720/Microsoft-Google-sweeten-online-service-SLAs