This article presents a reflexion on new forms of interaction not yet approached by the HCI community. It's the study of the convergences and divergences between the personalization seen under two complementary angles: direct marketing on the one hand, and person/system interfaces on the other hand. The multimodality has been studied since many years, and personalization has been used in marketing for a long time, but seldom, both were studied jointly. A prototype of multimodal user adapted E-commerce site is presented. That opens, according to us, many tracks of research on the personnalization/multimodality intersection.