In this paper I discuss the rhetorical structure of 104 direct sales letters based on the notion of genre (Swales, 1990, 1991, 1992; Halliday e Hasan, 1989) and on some studies on business letters (Santos, 1996; Cheung, 1993, e Bhatia, 1993a, b). The rhetorical structure is constituted by six moves: four obligatory (stablishing contact, offer, demanding actions and closing) and two optional (companies' credentials and enclosing documents). This moves had their frequencies observed, so I could find that not all obligatory moves happened to be present in all instances of the corpus, what brought about some discussions on the criteria we use to perform such classification. As a result, I propose two concepts: 1st essentiality vs non- essentiality which help to spot which movements are essential to the instantiation of the genre; and 2nd hierarchy, which is a means to evaluate how important a given step is to the instantiation of a move.
genre analysis; obligatory an optional moves; essentiality; hierarchy