Advertising is the art of persuasion. Still little is known about how words and images cooperate to produce convincing sales arguments; even less on how this interplay of modes has developed over time. Most of the linguistic research has focused on the properties of either the verbal or the visual, thereby separating what acts together as one meaningful unit. This paper explores the interaction of words and images in product print ads by charting the changes in argumentative strategies from the genre’s beginnings up to the present. Following a systemic functional approach (Halliday/Matthiessen 2014; Kress/van Leeuwen 1996; O'Halloran 2008), the quantitative and qualitative study, analysing a corpus of over 3,600 British, American and Australian print ads that date from 1652 to 2016, specifies how sales argumentation has evolved from a word-centered into a verbal-visual art. Amongst other results, it is shown that the move towards multimodal argumentation begins as early as 1730. Long before the use of illustrations, advertisers employ formatting and ‘type tricks’ to capture viewers’ attention and to accentuate product claims. From 1900 onwards, pictures take on a more extensive role. Although originally used to decorate the ad, imagery soon contributes to the sales argument by justifying, repeating or enhancing the verbal claim. Today, visuals provide more than just a 'flag' . Their form and style helps guide readers’ interpretation of the ad through the use of color, texture, framing and composition.

Halliday, M.A.K. and Matthiessen, Christian (2014) Halliday's introduction to functional grammar (4th ed.) London: Routledge.

Kress, Gunther and van Leeuwen, Theo (1996) Reading images: the grammar of visual design. London: Routledge.

O'Halloran, Kay (2008) Systemic functional-multimodal discourse analysis (SF-MDA): constructing ideational meaning using language and visual imagery, Visual Communication 7 (4), 443-475.