The document discusses how creating applications for Facebook can be an effective marketing tool. Facebook applications allow businesses to promote their brand, engage customers, increase traffic to their website, and gain new fans. Well-designed Facebook applications that are spread virally can provide cheap publicity and brand awareness. The document provides examples of different types of applications, such as games, quizzes, and microsites, that can communicate with Facebook data and external databases. It also notes that creating applications requires an understanding of technologies like Flash, JavaScript, and FBML. Businesses should use applications on Facebook to build their brand, engage customers, increase site traffic, and collect user data for further marketing.