Challenge operates a collection of popular French and Italian websites with the goal of aggregating high-quality second-hand products for sale in one central online location. They recognised an opportunity for a website that could help UK shoppers find the best bargains among these fluctuating prices of second-hand items, resulting in the launch of in early 2015. 

“Our users don’t want to waste their time scouring hundreds of websites, so we allow them to search our database for countless listings all in one place,” says Bart Verschueren of  

The idea was a hit. Months after launching, has seen traffic steadily increase 20% week over week. And, based on their other successful web projects, they knew there was a way to turn a profit from this endeavour. 


Because the team was already sourcing many of their items from eBay, they recognised that affiliate marketing could provide the company with a natural revenue stream, as well as access to eBay product deals that would draw a larger audience. The team at had worked with eBay Partner Network before, and this new venture seemed like a perfect match. could drive new eBay buyers, while driving affiliate earnings for the website. 


After joining eBay Partner Network, the team used eBay’s API to add more eBay product listings to the site. 

“Our goal is to provide our users with the highest quality used objects for their search and we utilise the eBay API to accomplish this,” says Verschueren.

eBay’s extensive list of search attributes enabled to create optimised search algorithms to find the best bargains within eBay’s millions of items for sale. The team customised the API calls to retrieve the most important product information, while honing in on only their niche of second-hand items. 

They also use ePN reporting to get insights into all transactions driven by their affiliate traffic. By tracking conversions and earnings, and identifying what pages work well and which need improvements, the team is able to optimise and continually improve not only the user experience, but also their affiliate earnings. 

“For us, this is where analysis becomes particularly motivating and valuable,” says Verschueren. “It allows us to verify hypotheses made when looking at weekly or monthly aggregates, with details from the lowest level of our dataset. That’s something most affiliate platforms can’t offer.” 

Verschueren recommends a deep dive into the transaction reporting to hypothesise, test and determine what is driving sales and new buyers, which helps the team earn extra revenue with ePN’s new buyer affiliate commission bonus. 

“Take time to understand the numbers and verify your tactics by setting up tests,” says Verschueren. “Building up insights like this will help you define your next steps.” 


By working with ePN to tap into eBay’s inventory, API and reporting tools, and combining it  with’s custom search engine technology to allow for real-time filtering, the result is a dramatically improved user experience that offers access to highly relevant products at the best prices. 

Since launch, traffic on has quickly increased to 800,000 visitors per month, and is on track to reach one million monthly visitors in the very near future. 

“Visitors now use our websites more regularly and efficiently,” says Verschueren. More success lies ahead for the company, which has taken the learnings from this project to launch German and US versions of the site with similar solutions and customer traction.