A cardboard salesman is like a snake oil salesman but of the modern era. Stupid ass products they sell may be things that you don't even need, like quesadilla makers or scams like a $30 laptop online
15-year-old trust fund kid: My stupid ass tried to buy a $5 1 TB USB online from a cardboard salesman
When someone puts their best foot forward in order to persuade one to buy the BS that they're selling.
The Relationship Salesman sold her way into a trillionaire's heart until the baby was born & then she divorced him and used him for alimony & child support.
A crafty smooth-talker dude who initially claims to just want a "first base" friendship with a lady, but in reality is merely using this assertion as an "opener" to eventually getting into her pants.
Hot chick: Brandon claimed he just wants to take me for strolls hand-in-hand... yeah, right... sounds like da classic "platonic bridge-salesman" pitch to me --- I've seen how he looks at me whenever I wear a swimsuit or a sun-dress!
To sell Chocolate, door to door to become rich enough, to take out a mom and her daughter on a date to Fancy restaurant under the sea in the Bikini Bottom.
Used in Sentence.
SpongeBob: Quick Patrick, without thinking, if you could have anything in the world right now, what would it be?
Patrick: Uhh...more time for thinking.
Sponge Bob: No, something real, an item, something you would pay for. Patrick: A chocolate bar?
Sponge Bob: That’s a great idea, Patrick! We’ll be TRAVELING CHOCOLATE-BARS SALESMAN.