title: (G.Analytics) How to add custom information to _addItem in ecommerce transaction
body: <p>When submitting a transaction (a new order) to Google Analytics, I'd like to add a custom parameter to the product item.</p>
  
  <p>The _addItem accepts the following parameters <a href="https://developers.google.com/analytics/devguides/collection/gajs/methods/gaJSApiEcommerce#_gat.GA_Tracker_._addItem" rel="nofollow">as explained here</a>:</p>
  
  <p>transactionId, sku, name, category, price, quantity</p>
  
  <p>I'd like to add a couple of custom parameters to this list (e.g. size, weight) - is this possible? Or should I use _setCustomVar <a href="https://developers.google.com/analytics/devguides/collection/gajs/gaTrackingCustomVariables" rel="nofollow">as explained here</a></p>
  
  <p>Thanks</p>