Offering free items is a way to get people to try their products.  It helps to build a customer base for them because people are more likely to buy from someone that they are familiar with the quality of their items.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi