I installed the Google javascript for conversion tracking on my confirmation page (my last page).
The problem is :
if a client save the confirmation page and open it 10 times on his computer the Google's script is called 10 times and Google reports 11 sales (the initial sale + 10 fake sales). But in real only one sale was done.
What can i do?
Due to this pb i cannot trust the sale reports from Google.
For me it's a small bug from Google, because they don't check the referrer of the calling page where the javascript is installed.
It counts subsequent hits by the same person as a transaction.
Therefore, you can just look at conversion reports and an individual opening the same page multiple times shouldn't change the conversions reported by Google, just transactions.
If the client open 10 times the saved page, in the report the Sales Count & Sales Value are : 11 sales & 11 x the price.
If this is a reoccurring problem for you, then maybe giving your clients a different page to save without the script, or refreshing the page to not include it, etc would be a solution for you.
You might want to ask how not to trigger a script like this upon second view or whatnot in one of the more technical forums.