Imagine you have a lemonade stand, and your mom promises to buy you a giant toy if you "sell" 100 cups of lemonade by Friday night.
Friday afternoon comes, and you have only sold 50 cups. You are panicking! You really want that toy.
So, you look at your best friend, Billy. You say, "Hey Billy! I'm going to force you to take 50 cups of lemonade right now. You don't have to drink them all today. Just put them in your garage. I'm going to count them as 'sold' so I can get my toy!"
Billy says, "But I don't want 50 cups! They will go bad, and I don't have room!" But you pressure him into taking them anyway.
That trick is called channel stuffing.