Touché is used as an acknowledgment during a discussion of a good or clever point, usually after
contradicting the user's previous point.
Adding 'salesman' to the end provides emphasis and a bit of humor, first used by
Peter Griffin in Family Guy. Although Peter was actually speaking to a
salesman, one doesn't necessarily need to be speaking to a salesman for this phrase to be used.
1) Peter: I'm pretty sure we've never had a volcano either.
Salesman: Well don't you think we're
overdue for one?
Peter:
Touché salesman.