Many businesses are choosing to move some servers off-site, to SNS's Data Center. Typically we will also use VMware to virtualize the infrastructure first, which helps create more recovery points and makes for a quicker recovery from a hardware failure.
In this scenario, an Off site "colo server" is used to back up the SQL data base Server, the Mail Server ( Microsoft Exchange 2003, Microsoft Exchange 2007, or Microsoft Exchange 2010 ), and a File Server. The file server often stores other backups of common office applications, such as from an ACT Server or Quickbooks server.