I have tried to fix this issue on the Google Analytics on E-Commerce tracking as they credit mostly transaction goes to sub-domain referral instead of original source of traffic like Organic keywords . As Google Analytics by Default, attribute transactions to the last referral. I have analyzed the path of visitors , they came across from Organic and go to another sub-domain and back to make the purchase in another sub-domain. The profile created by sub-domain by using filter hostname in each sub-domain and also keep default profile for all sub-domain.
What do you think how to solve this issue?