As the ruler of the market the consumer is supposed to indirectly tell the producer what and how much of that item they are supposed to make. They do this buy buying out an item that they really like which tells the producer that they need to make more and can possibly charge more for that product since so many people want it so bad. On the other end of that, when consumers don't purchase the product that is being sold then producers will either charge less because the price they have it listed for is too high or they will take the item entirely off the market because they are not making any profit off of it.