Trivago brought in over a billion euros in 2017, as the hotel search engine invested in development of its technology and advertising.
In full-year results released today, the company said it had seen revenue jump 37 per cent to €1.04bn (£920m).
Net loss for the year was €13m, less than a third of last year's €51.4m loss.
On an underlying basis the business was profitable with earnings before interest, tax depreciation and amortisation of €6.7m. But this was significantly smaller than earnings of €28.2m in 2016.
Speaking to City A.M. today, chief executive Rolf Schroemgens said that the company had invested heavily in its product and the technology behind it.
"At the end it's all about having the best product," he said.
"The majority of our efforts were in setting the infrastructure for the product up in a way that we can cope with the requirements of the future."
As part of this strategy, the company has made several acquisitions over the past year. In September it bought Tripl, a machine learning startup from Hamburg.
The company also said that increased advertising spend had helped to boost revenues. Schroemgens told City A.M. that advertising helped the company learn more about customers.
"We do a lot of quite extreme tests because the more extreme we do it the more information we get," he said, in reference to Trivago's near wall-to-wall advertising campaign on the London underground featuring "the Trivago girl", actress Gabrielle Miller.