There are several methods for delineating trade areas: the analog method, the proximal area method, and the gravity models. The analog method is nongeographic, and more recently is often implemented by regression analysis. The proximal area method and the gravity models are geographic approaches and can beneﬁt from GIS technologies. The analog and proximal area methods are fairly simple and are discussed in Section 4.1. The gravity models are the focus of this chapter and are covered in detail in Section 4.2. Because of this book’s emphasis on GIS applications, two case studies are presented in Sections 4.3 and 4.4 to illustrate how the two geographic methods (the proximal area method and the gravity models) are implemented in GIS. Case study 4A draws from traditional business geography, but with a fresh angle: instead of the typical retail store analysis, it analyzes the fan bases for two professional baseball teams in Chicago. Case study 4B demonstrates how the techniques of trade area analysis are used beyond retail studies. In this case, the methods are used in delineating hinterlands (inﬂuential areas) for major cities in northeast China. Delineation of hinterlands is an important task for regional planning. The chapter is concluded with some remarks in Section 4.5.