For building easily e-commerce applications, adaptive agent models are useful. These systems therefore should be equipped with the ability to improve their performances themselves, working over the basis of building a model with the goals, preferences and knowledge of each individual user in the environment. This paper presents a new architecture to support sales in Web stores centered on business based on product catalogs. The main goal of this architecture is focused on endowing capability of adaptivity in several ways: contents, navigation and presentation, while analyzing the different ways to develop the adaptivity in e-commerce.