Travelstart’s conversion lift experiment quantifies display ads’ impact

May 2018

Travelstart’s conversion lift experiment proves display’s impact on incremental visits and conversions


Increase market share and brand presence

Reach their growth objectives

Drive display performance


Launched dynamic remarketing campaign on Google Display Network

Conducted conversion lift experiment to measure causal impact on conversion and site visit behaviour


20.7% lift in site visitors

24.9% lift in page views

5.4% more conversions

10.6% greater conversion value

“The results completely exceeded our assumptions of the significance of non-direct conversion channels in assisting online sales.” – Thomas Kutama, Head of Performance Marketing, Travelstart

Travelstart’s mission is to save consumers time, money and stress with their simple online booking platform offering flights, hotel bookings, car rental, vacation packages and other travel services. Although they view conversion performance as key to success, they also wanted to increase market share and brand presence to reach their growth objectives, as well as get the best performance for their non-search efforts.

Travelstart launched a dynamic remarketing campaign on the Google Display Network to test the impact of display. Specifically, they were looking to discover whether users would have visited their website and converted regardless of being exposed to a remarketing display ad.

Together with Google, Travelstart conducted a conversion lift experiment to measure the campaign’s causal impact on conversion and site visit behaviour. The experiment split eligible users into treatment and control groups. In this setup, treatment users were shown Travelstart ads, while the ad was suppressed for the control group (these users instead were shown the next ad in the auction). The control group represented the environment that would exist if Travelstart were not running their display campaign.

The team measured how many users from the control group visited the Travelstart site and converted, and compared their behaviour to the treatment group of users who had viewed their display ads. The conversion lift experiment confirmed that dynamic remarketing ads generated incremental increases: 20.7% more site visitors, 24.9% more page views, 5.4% more conversions and 10.6% greater conversion value.

With these experiment results demonstrating that their remarketing activity is performing, Travelstart is extending their dynamic remarketing activity with Google into three key markets – Nigeria, Kenya and Egypt – and have adopted customer lifetime value as a metric to help improve the efficacy of their dynamic remarketing campaigns.

“As an online travel agent, we focus our marketing objectives around obvious conversion-driving channels”, observes Thomas Kutama, Travelstart’s Head of Performance Marketing. “It is difficult to validate upper-funnel activity if we cannot prove it contributes to sales. We used conversion lift experiments to affirm the role of display, and the results completely exceeded our assumptions of the significance of non-direct conversion channels in assisting online sales. We are now more confident to increase our activity in display and look forward to the value it brings.”

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