title: Mandrill - The difference between global_merge_vars and normal merge_vars
body: <p>I've looked at this <a href="http://help.mandrill.com/entries/21678522-How-do-I-use-merge-tags-to-add-dynamic-content-">Mandrill knowledgebase article</a> over and over and cannot see any obvious explanation of what the difference is between Global Merge Vars and Merge Vars, and when I should use global vs normal.</p>
  
  <p>Both global_merge_vars and merge_vars are declared within the 'message' object (as shown here in <a href="https://mandrillapp.com/api/docs/messages.html#method=send-template">the Mandrill API</a>), so it's not like you're declaring global_merge_vars outside the message object and then including multiple merge_vars.</p>
  
  <p>Also - is there any difference between how these are declared in the template itself or do they all just use *|MERGE_VAR_NAME|* format?</p>