You will find quite a few articles talking and comparing SharePoint online and on premise. I found an interesting post and just copy and paste below: In April 2011, Microsoft launched Office 365 – a comprehensive set of Software as a Service (SaaS) solutions that allow any organization to obtain hosted, cloud-based access to Exchange, Lync, Office Web Applications – and SharePoint Online . All offer guaranteed uptime, fault tolerance, contractual service levels, and clear, predictable pricing. How Do You Choose Between Cloud and On-Premises? Many organizations start by moving email to the cloud. Few organizations have highly customized Exchange email environments. For many, it’s a no-brainer to migrate existing mailboxes to a hosted version of Exchange, because it simplifies the level of infrastructure support for fault tolerance, recovery, web access, border security, and archiving. And, the services and configuration used for Exchange service on premises are usually the ...