Interface design and the interaction between customer and computer are factors critical to business effectiveness over the Web. A key aspect of conventional retailing is store layout; an analogous aspect in virtual retail is virtual store layout. This paper reports on an experimental investigation into the use of three different layouts in online grocery retailing: freeform, grid, and racetrack. These three most common conventional retailing layout types were transformed into virtual layouts for computer-mediated interfaces. Subjects in Greece and the UK participated in a laboratory experiment: they were given a planned shopping task with money to spend, and performed their shopping through a virtual store with layout as the manipulated variable. The results show that layout significantly affects online consumer behavior, but that predictions generated from the literature of conventional retailing about differences in the outcome of layouts do not generally hold in a virtual setting. Some of the findings can be explained by reference to research in Human Computer Interaction (HCI).