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Following the announcement of our acquisition of Addingwell last April, we sat down with Romain Baert, the company’s CEO, to discuss the story behind Addingwell, the growing importance of server-side tracking in the digital marketing ecosystem, and the strategic reasons behind the acquisition by Didomi.
It was an insightful conversation on today’s data challenges and a shared vision for more responsible and high-performing data management. Enjoy!
Addingwell: Origins, start, and growth
Can you tell us about the origins of Addingwell and your past experience that led to its creation?
There are two main pillars that guided the creation of Addingwell: why and how we decided to move toward server-side, and why server-side matters.
The story begins back when Julien, François, Jérôme, and I worked together at a company I co-founded: Mazeberry. Mazeberry was the French leader in marketing attribution, with a mission to help advertisers move beyond "last click" attribution models.
From 2015 until the start of Addingwell, we carried that message to the retail world, explaining that purchases don’t happen in a single click, but are part of a journey. However, analytics tools and platforms like Meta or TikTok often only highlight their own contribution, or rely on last-click data. Multitouch attribution was our focus for seven years.
What were the underlying issues with this cookie-based model?
We realized that the entire attribution engine was built on storing data through cookies. And the further we pushed the algorithms to refine the models, the more the quality of the data declined.
This degradation is well known, especially with the arrival of the GDPR. You can’t collect or process data, or place a tracker, without user consent. The market tried to find alternative trackers, but Data Protection Authorities (DPAs) clarified that this applies to all types of trackers, not just cookies.
On top of that, browsers introduced more restrictions: Apple removed third-party cookies and blocks certain scripts. Ad blockers are also becoming increasingly widespread.
How does this situation impact advertisers?
Advertisers are investing heavily in attribution tools (like Mazeberry at the time) or in CDPs for segmentation and retargeting. But under the surface, the data is steadily deteriorating. That’s when we realized that modern marketing couldn’t continue down this path: you can’t invest so much in martech if the data isn’t reliable.
And that’s where server-side comes in?
Exactly. At the same time, the market started talking about technologies like server-side, suggesting that tomorrow’s data must be accurate, first-party, and governable. These three keywords became the foundation of our research.
We saw that the client-side world (trackers in the browser) would gradually shift toward a more responsible and high-performing tracking approach, one that could overcome issues caused by browsers, ad blockers, and the end of third-party cookies.
So Addingwell invented server-side technology?
No, we didn’t invent server-side technology. It’s a data exchange model. Tag Management Systems (TMS) like Google Tag Manager have become server-side compatible, asking users to deploy their own servers.
We dug deeper and identified a technological shift: tech giants are turning to server-side to prepare for the end of third-party cookies and to improve data governance. Google Tag Manager, for example, calls itself "server-side ready."
So what’s the core problem, and what is Addingwell’s mission?
The big issue is that advertisers aren’t "ready." They don’t always realize they have data issues, they don’t fully understand what server-side means, and above all, they can’t easily implement such a project internally. It requires technical skills and IT resources that are already overstretched. Most company roadmaps are already packed.
The initial mission of Addingwell is to help the market adopt the new standards of digital marketing, starting with server-side tracking. We need to migrate quickly to these technologies in order not to lose momentum when it comes to attribution, marketing investment, or access to new features on major platforms.
Was your initial vision for the adoption of server-side different from the reality?
Yes, in the beginning, we thought server-side adoption would be a tidal wave, and that advertisers would quickly see the need for it. We were a bit naïve. Technically, it’s too complex for many of them, it requires too many resources, and most importantly, the environment is constantly shifting. Platforms release and change APIs, browsers update their rules, and ad blockers evolve. This constant change slows down adoption: some choose to wait despite poor data quality, while others don’t move forward because it feels too complicated.
That’s why Addingwell was created to simplify the transition. That’s actually the origin of the name "Addingwell": add your tags, go server-side, but add them well.
We realized the first real use case was simply migration. So we built a powerful, easy-to-use tool that enables any advertiser (from small e-commerce businesses to large international groups) to deploy their server-side infrastructure effortlessly. The core challenge is the same for everyone: invest in the right places and get the right return on investment.
How big is Addingwell today and how has its growth been?
Addingwell has been around for about three and a half years. We started in a garage-style setup, iterated constantly, and today, we’re a team of about 25 people with over 1,500 active clients. We also have a network of 200 partners who use Addingwell for their own clients.
Addingwell is more than a SaaS, it’s an ecosystem: we offer SaaS solutions for clients, a thriving community we actively support (with use cases, templates, documentation), and a network of partners.
We come from the startup world and are based at Euratechnologies in Lille. We’re bootstrapped, fully self-funded, with no outside fundraising. Our licensing model allowed us to fuel some pretty wild growth, nearly tripling in size every year. We currently gain between 70 and over 100 new clients per month.
Discovering server-side tagging and its rise
What types of advertisers are adopting server-side through Addingwell?
It started with e-commerce and retail, sectors where marketing spend is high and ROI is a central concern. But today, companies in media, travel, banking, insurance, and B2B have the same needs.
Anyone who invests in advertising wants a good return. There’s no minimum budget, even a small advertiser benefits from using Addingwell rather than spending blindly without solid data.
It sounds like server-side needed an evangelization phase. How did that unfold?
Yes, the first year was definitely about education. We had to explain what server-side was, why cookies were going away, and how you could gain 15–20% ROAS (Return on Ad Spend) optimization. People were convinced, but hesitant to be the first to jump in.
Fortunately, we weren’t alone on this path.
Players like Meta started publicly explaining that Apple had removed third-party cookies, that campaign performance had degraded, and that advertisers needed to shift toward server-side. Meta released an API that’s compatible with Google Tag Manager, and therefore with Addingwell. When advertisers spoke with their Meta account managers, they were encouraged to implement CAPI (Conversions API) which requires a server-side setup.
Addingwell was one of the first players to offer a fast migration solution. We even conducted an A/B performance test in collaboration with Meta for the Rocher Group (Yves Rocher), and published the results and a testimonial. That created a clear, proven use case and helped accelerate adoption.
There was another major shift related to data governance, wasn’t there?
Yes, a second shift, one that’s much closer to Didomi, helped democratize adoption around governance. For several months, Google Analytics was deemed illegal in Europe due to the Schrems directive and the transfer of personal data to the United States. The CNIL and other European DPAs ruled that using GA4 as-is was not compliant.
The only possible workaround was to connect Google Analytics via server-side. Why? Because your server can anonymize personal data before sending it to the U.S.This created a new governance use case for server-side. We had anticipated that server-side would boost data governance, because it's the only moment in the chain where the advertiser actually sees the data before it reaches any tool.
How does server-side improve governance compared to traditional methods?
Before server-side, even with a CMP, the advertiser acts as a data controller, obtains consent, and then tells partners: “You have consent, go ahead.” They open the door, and partners run code on their site, without the advertiser having visibility or control over what’s actually collected or sent.
Server-side changes all of that. When a user gives consent, the advertiser collects the data themselves, in accordance with that consent, and they decide what gets sent to Meta, Google Ads, Piano, or Google Analytics. These partners no longer run their code without the advertiser’s supervision.
This inherently enhances governance. A DPO sees server-side as a powerful tool for data governance. If someone asks what data is being collected and where it’s going, the advertiser can now see that on their own server, and can choose to modify, anonymize, or block the data flow entirely.
The acquisition of Addingwell by Didomi and the vision going forward
What was the reasoning behind the acquisition of Addingwell by Didomi?
There are two perspectives: why Addingwell chose Didomi, and why Didomi was interested in Addingwell.
From our side at Addingwell, a bootstrapped company in strong growth, one could ask why we’d join Didomi. Addingwell wasn’t a company looking to sell.
The major topic for Addingwell is international expansion. We’re pioneers and leaders in France. But to keep growing, we need to go international. That comes with changes and risks in areas where we’re not experts. Many entrepreneurs don’t receive enough support or move fast enough when going international. The server-side challenge is global. If we go it alone, country by country, we risk moving too slowly, and the market won’t wait.
Didomi, on the other hand, is already international. Over 50% of their revenue comes from outside France. They’re active in Canada, the U.S., Spain, the Netherlands, and more. They can easily distribute Addingwell’s product, because it aligns with their clients and brand. Plus, we share a very similar business philsophy with Didomi, focused on delivering premium, high-quality solutions.
For us, this was an opportunity to go international faster, with less risk. We found a partner who looks like us, and is highly motivated. That made us open our ears and start the conversation.
What is the future vision for Didomi and Addingwell products together?
The market’s reaction after the announcement was very positive. We received hundreds of messages congratulating us and saying, “This makes perfect sense.” The acquisition of a premium server-side leader by a premium CMP leader is logical. It’s a very horizontal play: every data collection starts with consent, and every data execution flows through server-side.
In this value chain, you need consent, proper data monitoring, strong server-side execution, and soon: effective analysis, execution, and segmentation. The project is supported by investor Marlin, with a strategy of bringing technologies together to offer more powerful solutions through horizontal growth.
What are the immediate and tangible benefits for clients?
In the short term, it’s about team integration. Advertisers will now speak with experts on both topics, without having to engage with two separate companies. It’s a real win for clients to address both consent and server-side topics in a unified way.
For server-side implementations, there’s always a DPO involved. With Didomi’s server-side offering, clients are guaranteed a setup that’s legal, aligned with their consent policy, and fully integrated with their CMP.
And in the longer term, what technological synergies are planned?
One of the first milestones following this technological alliance will focus on everything that can enhance the power of Didomi’s CMP. We know that server-side technology can significantly benefit the CMP, and we want to make that power accessible to all Didomi clients.
Like many other tools, the CMP is affected by the disappearance of cookies, the growing use of ad blockers, and the impact on web performance. A CMP that loads through a JavaScript script naturally affects performance, is blocked by some ad blockers, and struggles to maintain identity over time with the phase-out of first-party cookies on certain browsers.
Server-side technology can strengthen the Didomi CMP on all these fronts:
- A faster-loading CMP with reduced impact on website performance.
- A CMP that is resilient to ad blockers, improving the display rate of the consent banner. Today, 10 to 15% of users with ad blockers don’t even see the banner and can’t make a choice: that’s lost data. Server-side helps recover it.
- Better analysis of consent data, by preserving user identity and preference choices over time.
These use cases and integrations are already part of our upcoming roadmap.
The end of third-party cookies in Chrome: What impact on server-side?
Let’s talk about current events. Google recently announced another delay to the end of third-party cookies in Chrome. What’s your reaction or analysis?
That's right, the announcement happened on the same day we announced the acquisition.
The first thing to remember is that Google doesn’t dictate the rules for other browsers:Since 2020, third-party cookies have already disappeared from Apple (iOS), Edge, Brave, and Firefox. Google has lagged behind because of its advertising interests and the legal complexity tied to its dominant market position.
The company launched initiatives like the Privacy Sandbox to show advertisers what the future might look like. But for now, these solutions haven’t seen sufficient adoption.Moreover, Chrome is currently facing antitrust proceedings in the U.S., which will likely lead Google to redefine its roadmap. Any short-term move that could reinforce a dominant position is likely too risky.
In my view, Google’s announcement is highly political and tightly connected to current legal pressures.
But does Google’s announcement mean we should slow down server-side adoption?
Absolutely not. Chrome is a major player, but its market share varies depending on the sector. It’s lower in luxury or travel, for example, where iOS/Safari is more dominant. Every advertiser can check their non-Chrome audience share in their analytics.
Even without the end of third-party cookies in Chrome, server-side is already useful for the 50% (or more) of the audience that isn’t using Chrome. Today, server-side already enables up to 20% ROAS optimization, even with third-party cookies still active on Chrome. That’s huge.
And improving web performance through server-side also benefits Chrome users, since it boosts Web Vitals which directly improves SEO, a critical factor for advertisers.
This whole Chrome episode is a politicized pause, but we must keep preparing and understand that we can already have better attribution and personalized marketing for at least half of our audience that’s not on Chrome.It’s one step back to take a bigger leap forward.
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To learn more, visit Addingwell’s website and follow Romain on LinkedIn.
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