If the price of coffee decreases, how might this impact the demand for cream, a complementary good?

When coffee becomes cheaper, more people buy it, so the overall coffee consumption rises. Cream is used together with coffee, so the extra coffee buyers will also want more cream to go with it. Because more coffee is bought, the demand curve for cream shifts to the right, meaning the quantity demanded of cream increases at each price. For example, if the coffee price falls from $3 to $2, a coffee shop might see coffee sales jump from 100 cups to 150 cups, and the shop would likely need to add cream to serve the extra 50 cups. Thus, a price drop in coffee boosts the demand for its complementary good, cream.