Online platforms and digital advertising market study

The Competition and Markets Authority has completed its market study into online platforms and the digital advertising market in the UK.

Administration timetable

Date Action
1 July 2020 Publication of final report and decision not to make a market investigation reference
12 February 2020 Consultation on interim report closed
18 December 2019 Publication of interim report and consultation on whether to make a market investigation reference
30 July 2019 Deadline for responses to the invitation to comment
3 July 2019 Launch of market study

Final report

1 July 2020: We have published the final report of our market study into online platforms and digital advertising. We have found that competition is not working well in these markets, leading to substantial harm for consumers and society as a whole.

We recommend that the government passes legislation to establish a new pro-competition regulatory regime.

Responses to interim report

Penalty notice

17 January 2020: The CMA has published a notice (served 10 January 2020) of a penalty imposed on AppNexus Europe Limited under section 174A of the Enterprise Act 2002. The CMA imposed the penalty for a failure to comply, without reasonable excuse, with the requirements imposed on AppNexus Europe Limited by a notice issued by the CMA under section 174 of the Enterprise Act 2002.

Interim report

18 December 2019: We have published an update on our online platforms and digital advertising market study, setting out our initial findings, including the concerns we have identified and the potential interventions we are considering.

We are inviting comments on our report, including on our proposal not to make a market investigation reference at this stage, by 5pm on 12 February 2020.

Responses to Statement of Scope

Launch of the study

3 July 2019: The CMA has launched a market study into online platforms and the digital advertising market in the UK. We are assessing three broad potential sources of harm to consumers in connection with the market for digital advertising:

  • to what extent online platforms have market power in user-facing markets, and what impact this has on consumers
  • whether consumers are able and willing to control how data about them is used and collected by online platforms
  • whether competition in the digital advertising market may be distorted by any market power held by platforms

We are inviting comments by 30 July 2019 on the issues raised in the statement of scope, including from interested parties such as online platforms, advertisers, publishers, intermediaries within the ad tech stack, representative professional bodies, government and consumer groups.

Personal information

The CMA may collect, use and share personal data for its market studies under the Enterprise Act 2002. This includes processing personal data for the purposes of the General Data Protection Regulation and the Data Protection Act 2018.

For more information about how the CMA handles personal information, see the CMA’s Personal Information Charter.

Digital markets strategy

This study is part of the CMA’s Digital Markets Strategy, which sets out our broad approach to protecting consumers in the digital economy while ensuring robust, competitive digital markets.

Published 3 July 2019
Last updated 1 July 2020 + show all updates
  1. Final report, appendices, glossary and quantitative research report published.

  2. Responses to interim report published.

  3. Penalty notice published.

  4. Interim report published.

  5. Additional response to the Statement of Scope published.

  6. Additional response to Statement of Scope published.

  7. Responses to Statement of Scope published.

  8. First published.