British English has many words that make sales talk sound suspect.
Patter: A salesperson’s practiced, rapid talk.
Spiel: A sales speech that sounds rehearsed.
Flannel: Flattering talk that avoids the point.
The gift of the gab: The ability to talk easily and persuasively, not always a compliment.
A used-car salesman: Someone who seems pushy and untrustworthy.
To oversell: To claim more than something deserves, which makes people doubt it.