If Google were to degrade its search results by demoting links to better services, users would just switch to a rival service, such as Bing or DuckDuckGo.
But as digital platforms have grown ever bigger, that thinking has started to change, even in America.
A growing number of antitrust experts now accept the commission's view, that network effects create high barriers to entry in online markets.
This means that Google, for instance, can in fact degrade its search results selectively (and disadvantageously to its direct competitors) without having to fear that its users will defect, says Maurice Stucke of the University of Tennessee.
“We need these super-platforms to adhere to a principle of neutrality,” he says.
How can such a principle be enforced?
In the case at hand Google could just feed all search queries through one algorithm and do away with the second one that produces the Google Shopping results.
But what if this one algorithm still ends up putting Google's links on top?
Will the commission then force the firm to reveal its inner workings and even rewrite it?
If search algorithms become more personalised, as is expected to be the case with digital assistants such as Amazon's Alexa, it will be even more difficult to detect bias.