Qitzur Shulchan Arukh – 62:6
A store-owner may give out seeds and nuts to children so as to get them [i.e. their parents] in the habit of shopping by him. Similarly, he may sell at a cheaper price than the going rate so that they would buy from him. And [the others in] the marketplace are not able to stop him.
After looking at false advertising, the next step in the Qitzur is to discuss the forms of marketing that are allowed. Since everything is honest and up-front, being generous to the shoppers’ children or just underpricing the competition is permitted.