"Freebies" are items that are given away for free by a company to customers. Most often, these are intended to reward consumers, advertise the brand, or try to encourage more people to buy the products the company offers.
While "freebies" are free for the people who receive them, it is important to remember that they are not free for the company that produces them. "Freebies" have an impact on the manufacturers, the company that orders them, and even the environment. They can impact people in various ways. In the case of the people who produce them, they can represent an important cost that can sometimes be difficult to justify. In the case of the people who receive them, they can boost their interest on the brand.
A freebie I once received was a pair of sunglasses from a bank when I opened a new account. Although this did not change my relationship with the bank, it did give me a positive image of the bank, making me more likely to recommend it to friends.