Glossary of Platform Law and Policy Terms


Cite this article as:
Paddy Leerssen (17/12/2021). Microtargeting. In Belli, L.; Zingales, N. & Curzi, Y. (Eds.), Glossary of Platform Law and Policy Terms (online). FGV Direito Rio.

Author: Paddy Leerssen

Targeting is a practice whereby online content, typically advertising content, is distributed towards particular audiences based on their personal data. In the words of William Gorton, microtargeting involves “creating finely honed messages targeted at narrow categories of voters’ based on data analysis ‘garnered from individuals’ demographic characteristics and consumer and lifestyle” (Gorton, 2016)1. Targeting is often closely associated with personalization, and the terms are often used interchangeably. The prefix micro- is used to indicate that a highly specific audience is being targeted, although the precise criteria for this designation are rarely made explicit.

The most popular and influential microtargeting services are those offered by major online platforms such as Google and Facebook, but it is not limited to these services. Indeed, microtargeting can also be done offline; many offline campaign activities, such as door-to-door canvassing, pamphleteering, and telephone banking can be targeted with the help of personal data, much in the same way as online advertising.

When microtargeting relates to political advertisements, it is referred to as political microtargeting, which Ira Rubinstein describes as a form of “direct marketing in which political actors target personalized messages to individual voters by applying predictive modeling techniques to massive troves of voter data” (Rubinstein, 2014)2. It is worth noting, however, that the concept of ‘political’ advertising is also ambiguous and continues to be contested, with some focusing on a narrower category of election campaign ads and others extending the term to cover all political ‘issues’ – which is itself a highly amorphous category (Leerssen et al., 2019)3. This same ambiguity about the boundaries of the political also arises in the context of microtargeting.

The threshold where targeting becomes microtargeting is not always clear. One way to distinguish micro-targeting is by reference to the size of the audience targeted. Another is to focus on the granularity of the personal data involved. Along these lines, Dobber, Ó Fathaigh, and Zuiderveen Borgesius (2019)4 propose, in the context of political advertising, that “micro-targeting differs from regular targeting not necessarily in the size of the target audience, but rather in the level of homogeneity, perceived by the political advertiser”. In this reading, targeting an entire neighborhood with a single message constitutes regular targeting, whereas tailoring different messages to different users within the neighborhood, based on their personal data profiles, constitutes microtargeting. Overall, the available literature suggests a sliding scale between general and micro-targeting, rather than a strict binary.

‘Microtargeting’ is a novel concept from communications science without any clearly defined legal meaning. Although various laws affect the practice of targeted advertising, including data protection laws and campaign finance laws (Dobber, Ó Fathaigh, Zuiderveen  Borgesius, 2019), these have not historically relied explicitly on the concept of ‘targeting’ or ‘microtargeting’ in doing so. Only recently has the concept made its first appearance in official policymaking.

In its June 2020 resolution on competition policy, the European Parliament proposed a ban on micro-targeting performed by online platforms. The report “calls on the Commission to ban platforms from displaying micro-targeted advertisements and to increase transparency for users” (European Parliament, 2020)5. A further operationalization of this concept has not (yet) been proposed, although accompanying statements from the amendment’s author, Paul Tang (2020)6, appear to use microtargeting interchangeably with ‘personalization’ – suggesting a relatively low threshold that could potentially cover most if not all targeting practices involving personal data.

Occasionally, self-regulatory efforts by platforms and other online services also reference the concept of microtargeting. For instance, Google claimed that it had prohibited ‘microtargeting’ for political advertisements, by virtue of having restricted targeting options for these ads to a more limited selection: age, gender, and general location (Google, 2019)7.

In the context of political advertising and campaigning laws microtargeting practices are now under intense scrutiny in multiple jurisdictions – due to its role in the spread of disinformation and manipulative content –, with reforms recently completed or ongoing in, inter alia, Germany, France, the United Kingdom, the Netherlands, Sweden, Ireland, the United States, and Canada (for an overview, see IVIR, 20198. The European Commission has also singled out microtargeting as a point of attention in the ongoing Digital Services Act reforms. Until now, the majority of these laws and proposals have focused on issues such as campaign finance and transparency and have not (yet) tackled the legality of microtargeting as such.


  1. Gorton, W. A. (2016). Manipulating citizens: How political campaigns’ use of behavioral social science harms democracy. New Political Science38(1), 61-80.
  2. [Rubinstein, I. S. (2014). Voter privacy in the age of big data. Wis. L. Rev., 861.
  3. Leerssen, P. et al. (2018). Platform ad archives: Promises and pitfalls. Internet Policy Review8(4). Available at:
  4. Dobber, T., Ó Fathaigh, R., Zuiderveen Borgesius, F. (2019). The regulation of online political micro-targeting in Europe. Internet Policy Review8(4). Available at:
  5. .European Parliament. (2020). Resolution of 18 June 2020 on Competition Policy – Annual Report 2019. 2019/2131 (INI). Available at:
  6. Tang, Paul. (2020). European Parliament wants to forbid personalised advertisements. Available at:
  7. Google. (2019). An update on our political ads policy. Google Official Blog
  8. Van Hoboken, J., Appelman, N. Ó Fathaigh, R., Leerssen, P., McGonagle, T., van Ejick, N., Helberger, N. (2019). The legal framework on the dissemination of disinformation through Internet services and the regulation of political advertising: A report for the Ministry of the Interior and Kingdom Relations. Institute for Information Law. Available at:
Categorized as Entries

By Paddy Leerssen

Paddy Leerssen is a PhD Candidate in information law at the University of Amsterdam. His research focuses on the regulation and governance of social media platforms, with a particular focus on transparency and data access.

Leave a comment