In English Romantic Comedy movie Serendipity (2001), Jonathan Trager, Salesman & his friend Dane searching the information of Sara Thomas. Jonathan Trager has account number of her shopping bill. so Three went to storage facility in Queens to find her number or address. They somehow find carbon copy of the customer Sara in this facility, but improper handling of the copy which made them impossible to read details on it.
Salesman: When he grabbed it,his thumb went right across the right across the name. Completely. I'm kidding. It was smudged in my hand.
Salesman words made Dane angry started to fight, so Jonathan trying to stop him:
Jonathan: Would you stop it?
Salesman: It's just a little joke. That's carbon paper for you. I guess that's why America rejected it.
I didn't understand Salesman's words here about America & carbon paper.