With a market share of over 80%, the search engine Google is the dominant means for accessing online information. Today, there are hardly any search providers left that are able to compete with Google globally. Big players such as Yahoo and Ask have already given up the development of their own indexes, and Microsoft – despite playing an important role in the search market – has to subsidize its search operation bing substantially.

With a global market share of over 40%, the advertising company Google is also the dominant means for reaching online audiences with commercial messages. Through the acquisition of DoubleClick in 2008, Google was able to extend its advertising operations enormously, both in terms of the actual reach of the ad servers and in terms of the kind of services the company can offer. Starting off with simple search marketing via AdWords, Google today offers the whole breadth of online marketing tools from text ads to large display ads, from text matching to behavioural targeting.

There is no doubt that the dominance of a single company in both search and advertising – two fields that are central to the development of the web – are a cause for concern. Questions of bias and manipulation have been raised early on in academic research. What has emerged from these discussions is the insight that definitions of quality and relevance that are implemented in Google's ranking technologies have a profound impact on the means of accessing information, but also, via webmasters' search optimization practices, on the structure of the web itself. During recent years, the stream of critical voices has intensified, shifting focus to the problem of privacy and its demise in light of economic imperatives. A key issue in these debates is the question whether the burgeoning masses of user data collected by Google can be framed as exploitation.

In my paper, I will argue that discussions of bias, manipulation and exploitation in the area of web search have a lot to gain from a more explicit discussion of the term power. While the connection between these questions might seem obvious, it is remarkable that the term power – despite being used ubiquitously – is hardly ever defined explicitly. Given the extremely dynamic nature of the web, both in terms of technology, content, and economics, I will argue that it is crucial to discuss in how far the mechanisms of power itself are subject to change.