|TRIVAGO N.V. filed this Form 6-K on 10/24/2018|
% increase/(decrease) in click-out rate referrals
During the third quarter of 2018, RPQR decreased by 8% in Americas and increased by 13% and 1% in Developed Europe and RoW, respectively, as compared to the same period in 2017. Consolidated RPQR was flat as increased RPQR in Developed Europe and RoW was offset by lower RPQR in Americas. The decline in Americas was primarily driven by lower levels of commercialization, unfavorable foreign exchange rates of certain Latin American currencies against the euro and a shift towards lower RPQR locales. These effects were partly offset by a slight improvement in traffic quality. The increases in Developed Europe and RoW were a result of positive effects of increased CPC bids and significant improvement in traffic quality from the attribution model and platform optimization, partly offset by lower levels of commercialization. The decline in commercialization in Developed Europe in the third quarter of 2018 was less pronounced than in the other segments.
During the nine months ended September 30, 2018, RPQR decreased by 13% and 7% in Americas and RoW, respectively, while it increased by 3% in Developed Europe as compared to the same period in 2017. Consolidated RPQR decreased by 7% and was driven by decreased RPQR in Americas and RoW. The declines in Americas and RoW were due to persistently lower levels of commercialization and the negative foreign exchange effects described above, partly offset in RoW by the positive effects of improved traffic quality from the attribution model and platform optimizations. The increase in Developed Europe was driven by positive effects of improved traffic quality from the attribution model and platform optimizations, partly offset by the negative impact from lower levels of commercialization.
Return on Advertising Spend
We track the ratio of our Referral Revenue to our Advertising Spend, or ROAS. We believe that ROAS is an indicator of the effectiveness of our advertising and it is our primary operating metric.
The following table sets forth the ROAS for our reportable segments for the periods indicated:
Consolidated ROAS improved to 135.9% in the third quarter of 2018 and to 116.8% in the nine months ended September 30, 2018, respectively, compared to 110.9% and 114.7% in the same periods in 2017.
ROAS improved by 26.2 ppts, 21.3 ppts and 27.2 ppts in Americas, Developed Europe and RoW, respectively, in the third quarter of 2018, compared to the same period in 2017. As noted above, we made significant