This chapter explores how advertisements, as a type of public discourse, may “appropriate” the features of private or personal discourse (e.g., chats between friends) to fulfill particular communicative purposes and achieve good communicative effects. Focusing on style switching and genre hybridity in public discourse (particularly in advertising discourse), it seeks to explain how public discourse synchronically and diachronically presents the feature of personalization. By delving into the pragmatic motives and value orientations behind the generic “appropriation”, this chapter highlights that, while personalization is a manifestation and orientation of language civilization with regard to non-profitable public discourse, it is to a large extent a pragmatic strategy in the case of commercial advertisements.