trivago has reported that total revenue increased to €298.3 million in the second quarter of 2017 and €565.9 million in the six months ended June 30th, 2017.

Both figures represent a 67 per cent increase year-over-year, with increases were driven by a rise in advertising spend in both periods.

Referral revenue in the second quarter of 2017 increased significantly to €115.8 million, €120.6 million and €58.6 million, in Americas, developed Europe and rest of world, respectively, or 67, 45, and 137 per cent, respectively, as compared to the same period in 2016.

This increase was due to strong investment in advertising spend and included continued positive revenue effects from the introduction of our relevance assessment, which assesses the quality of users’ experience after leaving trivago’s website.

Strong referral revenue growth in all segments in the second quarter of 2017 was further positively impacted by reinvestment of profits into advertising spend, particularly in the developed Europe segment.

These drivers also led to solid growth in the six months ended June 30th, 2017, with referral revenue increasing 72, 44 and 134 per cent year-over-year in Americas, developed Europe and the rest of the world, respectively.

The growth in the rest of the world was mainly driven by increased marketing activities in Japan, India and Russia.

Axel Hefer, chief financial officer at trivago, said: “Our focus is on growth and long-term value creation when managing our business.

“In taking this direction, we have seen strong performance in quarter two of 2017 as our revenue has increased by 67 per cent year-over-year and our adjusted EBITDA by 39 per cent.”