In order for the products to be bought, the news must reach to the consumers. These marketing strategies like infomercials, sponsorships, and product placement are all for the dissemination of the company's name and reputation to the public. Sales and marketing are form of investments of big companies as global marketers. They are willing to give away money by sponsoring events and giving away freebies, all for the long term goal of gaining the trust of the buyers.
For example, Proctor and Gamble are very eager to sponsor significant events where intelligible people attend to. On the other perspective, they have food stands in malls that offer freebies and free tastes. They are extending a hand to the consumers so that they can try their products without any hesitation (because it's free). From there, it is the consumers' free will to be loyal to their products.