1. Log into PayPal.
2. Under the ‘My Account‘ tab click on the ‘Profile‘ link.
3. Click on ‘Website Payment Preferences‘ (under ‘My Selling Tools‘ in the right column).
4. Turn ‘Auto Return‘ on and enter the URL of your ecommerce thank you page which ishttp://www.your domain.com/finishorder.php .
Then add ?utm_nooverride=1 to the end of your URL; this will ensure that transactions (i.e. conversions) are credited to the original traffic source, rather than PayPal.
Now, if a visitor came from a Google search for ‘gardening book‘ the conversion will be credited to Google, organic, gardening book (and not PayPal, referral).
网站添加ga后，显示流量来源/媒介是paypal.com / referral
原文：http://www.cnblogs.com/you-jia/p/4545844.html