title: How to deactivate sold out products on Amazon MWS
body: <p>I'm implementing stock synchronisation with multiple sales channels - I'm struggling to find the best way to set products which have sold out to have a quantity of 0 (or deactivate).</p>
  
  <p>Amazon provides a flat file which can be used to manage price/quantity by SKU - this can then be uploaded via the Feeds API.</p>
  
  <p>However this specifies that the quantity must always be > 0, therefore will not work for for sold out products?</p>
  
  <p>Any suggestions on best way of keeping stock up to date?</p>