Trivago’s “relevance assessment dimension”, implemented in late 2016, is an algorithmic adjustment that compels hotel advertisers to improve their landing sites and booking engines if they want to rank higher in trivago’s search results. The idea is that while the user experience starts with a room search on trivago, it extends to when she clicks off to actually book the room on the advertiser’s site…so if the advertiser screws up that last step (according to trivago), it will have to pay more for each referral. One consequence of this change was that trivago penalized OTAs whose links sent users to yet another page of search results on OTA.com rather than directly to the property that the OTA listed on trivago.