This paper explores primary school children's ability to engage with "the power of the text" by tackling persuasive writing in the form of an advertisement. It is eclectically framed within genre theory and rhetorical studies and makes use of linguistic tools and concepts. The paper argues that writing research has not built upon earlier publications in these areas. There is a need for studies of advertisement writing to consolidate and extend the recent interest in non-fiction text types. The writing of two children, drawn from a much larger study, is used to provide evidence of some key features of advertisement writing. Use of a pro forma reveals how children imbue the power of their writing through a variety of techniques and suggests how these features may develop over time. It is argued that an understanding of advertisement writing warrants careful exploration, as persuasive writing is generally being given a more prominent place in curriculum provision in England. The paper concludes by noting the importance of ecological validity and pupil engagement when persuasive writing is tackled in schools. It also suggests the need for new kinds of customised analyses when further studies of this kind of writing are undertaken.