You shouldn't try to take advantage of people.
Sean is at a trading event for a popular card game and sees a person who has just started playing the game.
Sean wants to trade cards with the new player.
Sean looks at what the person has, makes some suggestions, and offers to trade some of his cards that would help the new player.
Sean picks out the person's best cards, says that they're not very good, and offers him a trade for some less-valuable cards.
The new person accepts the trade and builds a powerful deck that helps him succeed in future matches.
The new person accepts the trade, finds out that he gave up great cards, and becomes bitter towards other players.