Competition in Ad Tech: A Response to Google

100 Pages Posted: 29 Jun 2020 Last revised: 29 Mar 2021

See all articles by Damien Geradin

Damien Geradin

Tilburg Law and Economics Center (TILEC); University of East Anglia (UEA) - Centre for Competition Policy; Geradin Partners

Dimitrios Katsifis

Geradin Partners

Date Written: June 3, 2020


In May 2020, Google submitted an expert report co-authored by Daniel Bitton and Stephen Lewis to the ACCC in the context of the latter’s Ad Tech Inquiry (the "Google Report"). In their paper, the authors attempt to rebut the analysis we made in papers we published in 2019 and 2020 in which we exposed some of the conducts pursued by Google, the dominant provider of ad tech services, which we believe could breach competition rules. As we show in the present response, the Google Report is deficient in multiple respects. It includes misleading arguments, factual inaccuracies, multiple omissions, but also some interesting admissions.

Now, we are grateful to Google for commissioning and making public this Report. It is indeed the first time that Google provides such details about several controversial features of its ad tech products. In a world where Google typically communicates important product changes to its customers through Delphic blog posts, this Report offers us a rare opportunity to test our analysis. As the authors of the Report represent and advise Google on various matters involving ad tech, including investigations by several competition authorities across the globe, this Report offers a glimpse into the stories Google tells regulators.

In fact, the Google Report has made us even more confident on the strength of our arguments, which clearly show that Google’s conduct in the ad tech sector is problematic and should therefore be investigated. The Google Report does not contain a single valid criticism of our analysis. We are also astonished that, while the authors of the Google Report must have access to a large volume of data regarding Google’s ad tech business, they do not seek to rebut our analysis with any data point. The Report is essentially descriptive and, in most instances, seeks to challenge our analysis in a formal way, e.g., by extensively referring to Google’s own description of its products and tools.

Our reply is divided in five Parts. Part II provides an executive summary of our analysis of the Google Report. Part III offers some high-level remarks on the Google Report. Part IV addresses in detail the authors’ description of the evolution of RTB and Google Ad Manager, before responding in detail to their criticisms. Part V concludes. Finally, we include an Annex with several questions which regulators (including the ACCC) might consider addressing to Google in order to clear up various “misconceptions” around its ad tech business.

Keywords: Online Advertising, Display Advertising, Advertisers, Publishers, Auctions, Ad Exchange, Header Bidding, AMP, Digital Platforms, Ad Tech, Big Data, Google, Competition Law, Abuses of a Dominant Position, Exploitation, Vertical Foreclosure

JEL Classification: K21, L12, L41, L86, M37

Suggested Citation

Geradin, Damien and Katsifis, Dimitrios, Competition in Ad Tech: A Response to Google (June 3, 2020). TILEC Discussion Paper No. DP2020-038, Available at SSRN: or

Damien Geradin (Contact Author)

Tilburg Law and Economics Center (TILEC) ( email )

Warandelaan 2
Tilburg, 5000 LE

University of East Anglia (UEA) - Centre for Competition Policy ( email )

Norwich Research Park
Norwich, Norfolk NR47TJ
United Kingdom

Geradin Partners ( email )

Avenue Louise 475

Dimitrios Katsifis

Geradin Partners ( email )

Avenue Louise 475

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