This article describes a contrastive study on rhetorical differences between Italian and English sales promotion letters. It is assumed that cultural differences affect discourse genres traditionally considered as standardized, ritual or even formulaic, written business communication being a case in point. It was our goal to investigate how information is presented and what rhetorical strategies are used in order to obtain compliance by a given readership in a given culture. To answer these questions of an essentially pragmatic and ethnolinguistic nature, research focused on analyzing contrastively a corpus of authentic Italian and English business letters. Of course, within the genre "business letter" it is possible to distinguish sub-genres or repertoires (chasing money, requesting, offering, sales promotion, etc.). The letters in the corpus were classified according to these repertoires, defined on the basis of their prototypical discourse features as well as the specific social action within the business organization that they were meant to perform. Once classified, they were analysed according to two criteria. At the macro-textual level the analysis focused on rhetorical structure, mainly drawing on the notion of move. At the micro textual level the analysis concentrated on the pragmatic use of mood, modality, reference system and metadiscourse. This paper, in reporting the findings of the research project, will focus on the cultural preferences that Italian and English writers show--both at the macro- and micro-textual level--when engaged in sales promotion letter writing. It will be shown that there are differences in the ways in which discourse patterns are organized as well as in the use of mood and modality for the expression of politeness.