In Google Analytics, under the Ecommerce view, it shows direct/none for source/medium, as the 1st party cookie is lost when visiting the external SagePay checkout pages before the customer is redirected to my confirmation page which tracks the transaction.
In all the answers I have viewed when searching for a solution, the suggestion is to alter the tracking code to read
I just found this code:
var pageTracker = _gat._getTracker('UA-XXXXX-X');
pageTracker._setCampNameKey('ga_campaign'); // name
pageTracker._setCampMediumKey('ga_medium'); // medium
pageTracker._setCampSourceKey('ga_source'); // source
pageTracker._setCampNOKey('ga_nooverride'); // don't override
Could I store pre-checkout values for source/campaign/medium to a cookie and the retrieve it post-checkout into the code above, or would this start a new tracking session?