Final answer:
Advertising in monopolistic competition aims to differentiate products and can either make the perceived demand curve more inelastic or shift it to the right, resulting in increased sales and profits.
Step-by-step explanation:
In the framework of monopolistic competition, advertising serves to differentiate the products of one firm from another. It can affect a firm's perceived demand curve in two ways. Firstly, advertising can make the perceived demand curve become more inelastic, resulting in a steeper curve. Secondly, advertising can cause an increase in demand for the firm's product, leading to a shift of the perceived demand curve to the right.
A successful advertising campaign can enable a firm to sell a greater quantity of its products, charge a higher price, or both, ultimately increasing its profits.