212 13 Digital advertising Helen Kelly-Holmes Introduction Advertising was originally conceived as a one-to-many, primarily verbal/textual mode of com- munication. As web-based advertising evolved, it tended to retain these features; however, a number of developments have created parallel and powerful trends in digital marketing com- munication. The irst is the evolution of Web 2.0, characterised by user-generated content, peer-to-peer communication and interactivity, which has, on the one hand, forced advertisers to consider the interactive dimensions of their communication, and, on the other, enabled consumers to create texts about products, which are outside of the control of the advertiser. Consumers are thus in a powerful position to recommend products through electronic word of mouth (‘eWOM’), which can either reinforce or undermine the marketer’s message. The second development is the evolution of the concept of the ‘working consumer’ who co-creates value for brands and products; this, too, involves a loss of control on the part of the advertiser as communicator, since the consumer can also devalue a product or brand or subvert message content through remediation and comment. The inal dimension is the increasing role of ‘per- sonalisation’ in web-based advertising and marketing, which allows for customised and localised oferings to be made to consumers on an individual or one-to-one basis. Following an introduc- tion to digital advertising and a brief history of its evolution, these key factors and trends will be discussed in terms of current research and illustrative examples, and methodological approaches for exploring and investigating advertising and digital communication will also be addressed. Historical overview While it may not be as apparent as in traditional media such as print, radio, and television, the web and other digital media are primarily funded by advertising. From the marketing point of view, media (traditional and digital) are where promotion – in the form of advertising – takes place. Promotion is one of the ‘four Ps’ in the standard marketing mix, along with price, product and place; this mix has traditionally been the focus of marketers, with each dimension requir- ing equal but distinct attention and strategy. In contrast to earlier media, however, which were mainly focussed on promotion, the web and other digital media are able not only to promote products, but also to act as distribution and transaction channels as well. Consequently, the web