To copy a Campaign into the same account, click the dropdown arrow on the right hand side of the campaign and click 'Copy'. If you wish to copy the campaign into a different account choose the Copy To option.
You will then be prompted for a ‘Campaign Title’ in the ‘Copy Campaign’ window. Enter a title for your Campaign and click 'Copy'.
To include groups and recipients click the tick box named ‘include groups and recipients’. If you wish to edit the copied Campaign directly after creation then click the ‘Copy & Edit’ button.