I have just made a purchase on Folksy I had a bit of a delay trying to get into paypal to complete the transaction. While I was waiting I received the “congratulations on your purchase” email on my phone. I knew that I hadn’t because I was still waiting for access to paypal. At that point a customer might have given up to try later and changed their mind in that time. The item would show as sold to the seller but waiting payment. It surprised me to get the notification when I knew I hadn’t completed it. It doesn’t explain why buyers ignore emails maybe they are embarrassed but it might explain how sales with non payers happens.