From 2008, Google began to implement in European markets a fundamental change in strategy to push its comparison shopping service. This strategy relied on Google's dominance in general internet search, instead of competition on the merits in comparison shopping markets:
Google has systematically given prominent placement to its own comparison shopping service: when a consumer enters a query into the Google search engine in relation to which Google's comparison shopping service wants to show results, these are displayed at or near the top of the search results.
Google has demoted rival comparison shopping services in its search results: rival comparison shopping services appear in Google's search results on the basis of Google's generic search algorithms. Google has included a number of criteria in these algorithms, as a result of which rival comparison shopping services are demoted. Evidence shows that even the most highly ranked rival service appears on average only on page four of Google's search results, and others appear even further down. Google's own comparison shopping service is not subject to Google's generic search algorithms, including such demotions.
As a result, Google's comparison shopping service is much more visible to consumers in Google's search results, whilst rival comparison shopping services are much less visible.
The evidence shows that consumers click far more often on results that are more visible, i.e. the results appearing higher up in Google's search results. Even on a desktop, the ten highest-ranking generic search results on page 1 together generally receive approximately 95% of all clicks on generic search results (with the top result receiving about 35% of all the clicks). The first result on page 2 of Google's generic search results receives only about 1% of all clicks. This cannot just be explained by the fact that the first result is more relevant, because evidence also shows that moving the first result to the third rank leads to a reduction in the number of clicks by about 50%. The effects on mobile devices are even more pronounced given the much smaller screen size.
This means that by giving prominent placement only to its own comparison shopping service and by demoting competitors, Google has given its own comparison shopping service a significant advantage compared to rivals.