Many stores need an automatic return to register the conversion for Google eCommerce. By limiting the SIM method to a manual click by the customer causes a high degree of abandonment at the payment completion stage and therefore, no conversion registered with Google eCommerce. It does work as it should if authorize.net's domain is excluded in the Google eCommerce settings AND the customer clicks on the authorize.net receipt page button. HOWEVER, many times, they don't.
This is aggravated by the fact that the receipt page proclaims "Thank you for your order!" in bold text that is hard-coded and cannot be changed by the merchant. This reinforces the impression to the customer that he is done and exacerbates the abandonment issue.
The Relay Response method DOES NOT WORK correctly when using SIM, and Silent Post URL does not send the information needed to clear the customer's cart in the store.
DPM is out of the question due to issues regarding that approach not actually lessening scope of PCI compliance. Officers at companies like Trustwave state that it puts the store completely in-scope and is no different than AIM, regardless of claims that by Authorize.net that DPM lessens scope.
There are 2 things that need to be addressed and modified in the SIM receipt page:
1. There should be an option for the post back to the merchant store using SIM be automatic and not wait for user input on a receipt page. (Again Relay Response does NOT work!)
2. The field that states success on the receipt page ("Thank you for your order!") should be editable text by the merchant for situations where the receipt page IS displayed but a different message is desired.
Please consider these two minor modifications to the SIM platform. They would be a great benefit to many, many merchants, especially those using conversion tracking systems.