|TRIVAGO N.V. filed this Form 6-K on 10/24/2018|
million or by 1% in RoW as compared to the same period in 2017. Referral Revenue in Americas was negatively impacted by the decline in Qualified Referrals reflecting the reductions in our Advertising Spend and lower commercialization, as well as unfavorable foreign exchange effects, reflecting the relative weakening of the U.S. dollar to the euro. Referral Revenue in Developed Europe was negatively impacted by a decline in Qualified Referrals, reflecting the reductions in our Advertising Spend and lower levels of commercialization, which was partly compensated by improved traffic quality. Referral Revenue in RoW increased slightly compared to the same period in 2017 as the positive effects from increased Qualified Referrals and improved traffic quality were largely offset by declining levels of commercialization and unfavorable foreign exchange effects, reflecting the relative weakening of the U.S. dollar and certain currencies in the Asia Pacific region to the euro.
Other Revenue decreased by 22% to €3.2 million in the third quarter as compared to the same period in 2017 mainly due to the deconsolidation of myhotelshop in December 2017. In the nine months ended September 30, 2018, other revenue decreased by 2% to €10.6 million.
Qualified Referrals by Segment (in millions)
Note: Some figures may not add due to rounding.
Qualified Referrals in the third quarter of 2018 decreased year-over-year in all segments as the result of reductions in our Advertising Spend in the third quarter of 2018. All segments reflected the negative impacts of reduced click-out rates due to the completed roll-out of the attribution model and ongoing product optimizations. The decline in Americas was primarily driven by a reduction in marketing spend in North America. The decline in Developed Europe was due to a reduction in our brand marketing spend and an increase in the profitability targets in our performance marketing campaigns. The slight decline in RoW was driven by increasing profitability targets in our performance marketing campaigns while the decline in branded marketing spend in that segment had a minimal impact on Qualified Referrals.
Qualified Referrals in the nine months ended September 30, 2018 decreased in Americas and Developed Europe, while they increased in RoW compared to the same period in 2017. The decrease in Americas was due to the decline in Qualified Referrals in the second and third quarters of 2018 due to a reduction in our Advertising Spend, which was partly offset by the positive growth in Qualified Referrals in the first quarter of 2018. The decrease in Developed Europe was primarily due to a decline in the second and third quarter of 2018 reflecting a reduction in our Advertising Spend. The increase in RoW was driven by a strong increase in the first quarter of 2018 reflecting increased Advertising Spend, which was partly offset by the decline in the second and third quarters of 2018. All segments reflected the impact on click-out rates from the attribution model and product optimizations noted above.