What you need to know:

• The European Commission has launched an antitrust investigation into Google's advertising practices. 
• Self-preferencing of its owned ad stack is at the heart of the case. 
• “We will also be looking at Google's policies on user tracking to make sure they are in line with fair competition,” per EC Executive Vice President, Margrethe Vestager.
• It's the latest of Google's regulatory battles.
• In Australia, the ACCC's adtech supply chain report is due within six weeks.

One stack to rule them all

The European Commission (EC) has opened a formal investigation into Google and whether it violated European competition rules by favouring its own display advertising technology services.

In a statement released on Tuesday, the EC’s Executive Vice President, Margrethe Vestager, said there were serious concerns about a violation of antitrust law as Google acts as collector of data, seller of inventory and intermediary.

“Google is present at almost all levels of the supply chain for online display advertising. We are concerned that Google has made it harder for rival online advertising services to compete in the so-called ad tech stack,” she said.

'Fair competition'

“A level playing field is of the essence for everyone in the supply chain. Fair competition is important – both for advertisers to reach consumers on publishers' sites and for publishers to sell their space to advertisers, to generate revenues and funding for content.  

“We will also be looking at Google's policies on user tracking to make sure they are in line with fair competition.”

While Google’s business is under investigation in multiple jurisdictions – earlier this month, the tech giant agreed to pay a $268 million fine to settle an antitrust case in France – this investigation will look at different areas, like Google’s mandated use of Display & Video 360 (DV360) and Google Ads to buy inventory on YouTube, which over the last few years has been the death knell for some adech firms.

As AdExchanger reported, the decision to cut off third-party access to YouTube display ads was “devastating” for businesses like AppNexus.

Per the EC statement, the case will examine:

• Google’s restrictions on the ability of advertisers, publishers or competing ad tech firms to access data about user identity or user behaviour which is available to Google's own advertising intermediation services like Doubleclick ID.
• Google's plans to phase out third-party ‘cookies' on Chrome and replace them with the Privacy Sandbox tools. The investigation will also look at the effects of this on online display advertising and online display advertising intermediation markets.
• Google's plans to stop making the advertising identifier available to third parties on Android smart mobile devices when a user opts out of personalised advertising.

If proven, the practices the EC is investigating “may breach EU competition rules on anticompetitive agreements between companies… and/or on the abuse of a dominant position.”

Google is facing cases in the US, where the Department of Justice is suing Google for alleged monopolistic behaviour and an antitrust complaint has been brought by several states (but led by Texas).

In the case in France, Google requested a settlement and did not dispute the facts. It has agreed to a set of commitments that, among other things, “improve interoperability between Ad Manager and third-party servers”.

A spokesperson for Google told CNBC: “Thousands of European businesses use our advertising products to reach new customers and fund their websites every single day. They choose them because they’re competitive and effective.

“We will continue to engage constructively with the European Commission to answer their questions and demonstrate the benefits of our products to European businesses and consumers.”