A growing number of mergers and their potentially negative impacts on consumer welfare in the retailing sector have prompted discussion on how to define the boundaries of the relevant market. This article explores the boundaries of the geographic market of daily consumer goods through an examination of factors that influence shoppers' mobility in Croatia. The study takes into consideration the purpose of the trip and differentiates between major and fill‐in shopping trips, and demonstrates that different factors impact the shopper mobility for each of the two shopping trips. It provides support for the practice of defining market boundaries empirically on the basis of region and store format specificities, taking into account prevalent shopping occasion, economic situation of the residents, size of the residential area, and geographical placement of the stores among other things. The study shows that the boundaries of the retail market may be more narrow than expected.