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Who is Jonas Timmer?

Jonas Timmer is a Conversion Rate Optimization (CRO) specialist at Nu.nl, part of DPG, who has transitioned from a generalist to an expert in A/B testing. “I aim to improve Nu.nl’s platform, both app and web, focusing on user engagement and monetization,” Jonas explains. Over the past year, Jonas and his team have conducted nearly 100 experiments, a personal milestone he’s proud of.

Jonas brings a wealth of experience from his previous role at an agency where he focused on e-commerce. He found transitioning from an agency to an in-house role a significant shift, allowing for more in-depth specialization. “I taught myself basic coding within two months because we had a development capacity issue,” he says, illustrating his proactive approach to overcoming challenges in the experimentation field.

From Coding to Optimizing: Jonas’s Journey at Nu.nl

The switch from an agency to client-side work has allowed Jonas to delve deeper into CRO practices. “At an agency, you often need to be a ‘T-shaped marketer’—knowing a little about everything,” Jonas says. “But at Nu.nl, I became a CRO specialist, which was exactly what I wanted.”

Jonas’s passion for learning didn’t stop there. He taught himself HTML, CSS, and JavaScript out of necessity and interest, reducing dependence on external developers and speeding up the testing process. “I wanted to be less dependent on others,” he reflects, highlighting how this new skill set enabled him to run more complex and timely experiments.

Experimentation Superpower: Enthusiasm and Analytical Prowess

When asked about his “superpower” in the experimentation field, Jonas had to think for a moment. “I’d say my ability to get people excited about CRO is a key strength,” he eventually shares. While he is skilled in analysis, Jonas believes his enthusiasm for results—whether positive or negative—encourages others to listen and engage with the data. “I can provide the data, but it’s my excitement over any outcome that keeps people interested,” he adds.

Jonas regularly hosts a “CRO and UX moment” once a month with his UX research colleague Arie Bart, where they present monthly learnings to the team. These sessions, which even have their own theme tune, have become a staple at Nu.nl, showcasing both successes and failures. “When a hypothesis doesn’t work out, it’s an opportunity to understand why,” Jonas explains, emphasizing the value of negative results in driving further experimentation.

A Proud Experimentation Moment: From Frustration to Innovation

Reflecting on his proudest experiment, Jonas recalls a project for a client in the beauty industry. “It stemmed from my personal frustration with discount codes on e-commerce sites,” Jonas laughs. He noticed that placing a discount code field on the checkout page often led customers to abandon their cart in search of a code. Jonas proposed a creative solution: a special page accessible only through Google search results, offering a small discount to users who actively searched for codes.

The experiment didn’t stop there. Jonas also implemented a system where, after two failed attempts at entering a discount code, users were automatically given a 5% discount. “This led to a significant increase in conversion rates,” he shares.

Overcoming Challenges: The Battle Against “Gut Feelings”

Like any experimentation journey, Jonas’s path is not without challenges. One major obstacle he faces is stakeholders making decisions based on instinct rather than data. “People sometimes say, ‘I think this button should be here,’ without any reasoning,” Jonas explains. To counter this, he encourages deeper questioning and testing. “I often ask, ‘Why do you think that?’ and then suggest we test it to see what the data says,” he says, demonstrating his commitment to data-driven decisions.

Jonas believes in collaborating closely with UX researchers to gain deeper insights into user behavior. “Sometimes, data alone isn’t enough,” he notes. “We combine quantitative results with qualitative research to provide a full picture.”

The Role of AI in Experimentation: A Game Changer

Jonas also sees AI as a revolutionary tool in his experimentation work. Initially skeptical, he began using ChatGPT to help with coding issues and found it invaluable. “I tested it with some code, and it not only fixed my problem but explained the solution,” Jonas shares. This new capability doubled his output, allowing him to run about 100 experiments a year.

He sees further potential for AI in performing statistical analyses and automating processes within Nu.nl. “AI-generated summaries have already proven helpful in making longer articles more accessible,” Jonas adds, showing his enthusiasm for expanding AI’s role in experimentation.

Advice for Aspiring Experimentation Heroes

For those looking to follow in his footsteps, Jonas offers this advice: “Surround yourself with people who are enthusiastic about experimentation. It’s a lonely job otherwise,” he warns. He emphasizes the importance of resilience, learning from both positive and negative results, and not taking things personally. “Experimentation is about trying, failing, and trying again,” he concludes.

With his innovative mindset and passion for experimentation, Jonas Timmer exemplifies what it means to be an Experimentation Hero. His journey at Nu.nl continues to inspire and pave the way for future heroes in the field.

Joshua Kreuger

Programmamanager CRO/CXO circulation bij DPG Media

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