Under its licence and in accordance to the Postal Service Act 2011, Royal Mail are obliged to provide a Universal Service to UK residents, many people still rely on the postal service as a key way of communicating, especially for those that aren't computer literate or who simply prefer a letter through the door.
However certain areas come at an additional cost to the government because of their location; Orkney, Shetlands and the Outer Hebrides are difficult to access so they're considered long-term exceptions. This applies to mainly island addresses and a few parts of the mainland where the only access to post offices and post boxes are by ferry, air or boat.
If an Independent Scotland hoped to run a service similar to the postal service Royal Mail offers today then business secretary Vince Cable believes it "would be ‘significantly costly' and the knock on effect would be an increase in stamp prices or bigger subsidies.
Scottish ministers believe a publicly owned postal service in Scotland wouldn't need to generate vast profits, allowing Scotland to maintain current stamp prices by servicing the needs of Scotland and not shareholders.
More current industry news can be found here - http://www.otmltd.com/