We've been using Google Analytics reporting for some time now and we tend to focus on GA > Conversions > Ecommerce > Transactions (on left hand menu)
- "Transaction" listing all orders with a transaction id e.g. SESS123_name
- "Revenue" listing €amount
- "Tax" listing €amount
- "Shipping" listing €amount
and finally "Quantity" we show transaction numbers.
Yesterday (and now today), we have noticed that the Quantity column numbers are doubling to what we see when we view a transaction in detail
e.g Quantity = 4 then you click on the Transaction ID and it shows = 2