A method used by your friendly, self-motivated drug-dealer to try and squeeze you for more money.
When your dealer bestows upon you, out of the goodness of his heart, a free bag of better/more expensive product that makes what you usually get from him now seem like a bag of crappy-ass shit. Of course he would deny trying to Up-Sell, but is hoping to turn your usual $100 order into a $200 order, having shown you what you are missing. He might also step up the game by making sure your $100 bag now goes down in quality each time you buy, just enough to be noticed by you but not seem obviously intentional by him.
The "art" of tacking on high-priced options to an existing sale under the guise of customer service.
Every time Bill turns on his Sprint phone, it tries to upsell him on their backup service.