Adding Traction to the U.K.’s Most Popular Car Marketplace

Autotrader has connected customers with cars for half a century, starting as a printed classifieds magazine. The brand has a long history, but does not have a heritage mindset. It's an agile and evolving business that pioneered online buying and selling of cars in 1997.

After publishing its last physical magazine in 2013, it became a data-driven, online-only platform featuring 450,000 cars daily and providing access to over 80% of U.K. automotive retailers.

The Autotrader app, used by over 3 million people each month, offers the biggest choice of vehicles from private and trade sellers.

Autotrader is best known as a place to buy used vehicles, but new vehicle sales were added to the app in 2019 and became an important strategic growth area for the business in 2024 and 2025.

New U.K. license plates come out in March each year, so the Q1 period is essential for informing and inspiring customers about new cars with top-quality creatives.

The challenge for RTB House was to support these activities, bringing users back to the app to view new vehicles—which are more expensive than other listings—and then encouraging them to convert that interest into actions. Autotrader set strict CPA targets to make sure that campaigns were efficient.

Our solution first took shape in our in-house creative studio, where we developed state-of-the-art dynamic creatives that incorporated the iconic bold red color of the Autotrader brand and would show vehicles at their very best.

We then created both template and customized banners, which would display the best possible new vehicle recommendations to users based on their app browsing history.

This hyper-personalized targeting was powered by our Deep Learning algorithms and our ability to convert Autotrader’s vast data pools into structured insight applicable to individual users.

Classifieds sites have unique mechanisms that make campaign measurement different from typical stores or retailers. Each conversion is termed as a “lead” by Autotrader, and occurs when a user clicks in the app to contact or locate a dealership with the intention of finding out more about a new car.

Compared to our targets and other channels, our ads were exceptional. We delivered 92% more leads than Autotrader's target and outperformed other channels by 51%, all while falling well within our strict CPA goal. RTB House ads also drove users to take action more often, leading to a 2X higher click-through rate (CTR) than other channels.

Autotrader has been thrilled with the results from the first year of partnership, and we hope to explore campaigns that will continue to fuel their app and web activities in the future.