Marketing data foundation – Why data is so crucial for performance marketing

When I started at my previous company – EIGENSONNE – I was lucky to start the same day as a new colleague. The newly hired colleague was the company’s first data employee. I was the first marketing employee.

I cannot emphasize enough how important data is to build Performance Marketing.

You could actually stop reading now and get the main message of this post 🙂

If I remember correctly, all I had to work with was a (back then still) Google Data Studio report with wrong attribution and wrong channel naming…

So I obviously didn’t use it much ^^

So what did I begin with?

I tackled the obvious low-hanging fruits of our marketing accounts. I created a strategy with a roadmap.

And I started working on new reports.

As much as I write “I”, I should give all the credit to my colleague from data: she built the company’s entire data infrastructure and my reports in just two months, which sounds like a long time, but it was a huge job.

My role in this: create the specifications as exact as possible: report goal, metrics, dimensions, filters, hierarchy, etc

After 2 months, I had wonderful reports I could work with to monitor our lead acquisition, our geographical steering (regionality was significant for the company), the quality of our leads, etc.

So wonderful that they are still in use at the moment and daily used.

Here is an example of my favourite report, lead acquisition and main funnel events by timeframe.

What information is in this report?

  • Number of leads by chosen timeframe from our CRM
  • Possibility to see for each medium, each source and each campaign (you could actually get deeper with content and term)
  • Costs from the respective marketing platforms
  • Calculated metrics such as Cost per Lead. The marketing KPI (even if I battled against it, see below).

And let’s not stop here. We also had:

  • Total opportunities
  • Cost per opportunity
  • Total orders 
  • Cost per order
  • Revenue
  • Return On Ad Spend (ROAS)

These last metrics were reported by cohorts. Therefore, we would see how many opportunities, orders and revenue were generated from the leads acquired during this timeframe.

But why is data so important for performance marketing??

I just showed you one report. Cool.

Let me explain why this is so crucial.

1. Source of truth

In short: which numbers should you trust and work with? 

The ones from your company’s backend.

Don’t trust Google Ads, Meta or even Google Analytics numbers.

Marketing platforms such as Google Ads or Meta would try to take credit for as many conversions as possible.

Google Analytics then?

Mmh have you heard of deprecating third-party cookies? Ad blockers?

In a first-party context with a server-side tracking setup? You still need to respect users’ consent and won’t see numbers for users that don’t want to be tracked.

No, in the end, the numbers from your CRM are the ones to work with. And this is exactly what we saw in the dashboard I posted earlier. It is connected to the company’s CRM and reports the number of leads registered.

Neither what Google tracked via GA4 nor via Google Ads.

It is critical in every business model, but especially in lead generation models. Why? 

As soon as a lead is generated, there is still a funnel to follow. Yours is the first step, the entrance gate. So you definitely need to connect the gate to the rest of the pipe.

2. Connect the dots and speak the same language as your colleagues

Once your leads enter the funnel, they still need to convert and therefore have many touchpoints before converting into revenue. The rest of the business will work with CRM data and you need to connect the dots. 

You have different meetings with teams responsible for other parts of the sales funnel. You need to speak the same language, which means you need the same numbers to analyse the funnel and take actions if necessary.

By coming with GA4 numbers, you will confuse everyone, because they will have another number of incoming leads, therefore a different conversion rate. This will have a different impact on everyone’s job.

And you definitely need to make this effort, otherwise your entire value chain will work in silos. Remember that you are the gateway, so every analysis starts with your numbers.

By avoiding silos, you avoid teams to blame each other as no one agrees on common numbers. No coordination. No way to find issues in the sales funnel early before they hinder your growth.

At that point you understand how crucial it is to work with CRM numbers as a source of truth and to connect the dots between different steps in the funnel.

The beauty of it now is that you can use this data to improve your lead generation activity.

And if you start working with CRM data and connect the dots between each step of the sales funnel and the leads you brought in, you now know how much your leads convert.

3. Improve performance marketing activity

From the report above, you know how many leads you generate every day let’s say. And you know how they convert down the sales funnel.

It’s time to get deeper insights.


Segment your cohorts: demographics, geography, acquisition channels, industry-specific criteria, etc.

You will start to see which leads are of higher value to your business. You might then try to target only these or adjust your bid strategy to get more of them.

And here is my main advice from this article for you, dear Performance Marketer_in:

Don’t restrict your vision to just the marketing department. You’re employed by a company not by a department. Have a holistic vision. And do what’s most beneficial for the company.

(And if by degrading your personal goal, you actually increase the company’s goal, your goal is wrong).

I always take the following example:

If I go in my neighbourhood, I’m sure I can get 100 leads easily. And pretty cheap.

1000€ spent. 100 leads. 10€ CPL.

How many of them will convert down the sales funnel?


Totally random targeting, no message (I just promised them 10€ against their personal information). Bad quality.

But my CPL is good right? So should I continue?

The answer is obvious.



No, of course no.

What if – with the same budget – I targeted 10 super relevant leads that fit our customer profile?

1000€ spent. 10 leads. 100€ CPL.

How many of them will convert down the sales funnel?

Probably more than 0.

We can’t say a number for sure but the odds that someone converts are immensly higher with these 10 high-quality leads.

So it is definitely worth paying more for leads because you might have revenue down the line.


One of your first tasks – and the most critical one – when you start a job as a Performance Marketer_in: check the data infrastructure for marketing and create one if it doesn’t exist yet.

Without it, you can’t do a good job.

And even if you think you can optimise lead generation campaigns, you might not optimise them correctly.

Moreover it is imperative for the company you’re working for to have a source of truth that everyone can work with. All the business teams will align, work hand in hand and identify issues in the sales funnel early enough.

Finally you will be able to optimise not necessarily for lead generation but rather for order generation as you’ll know which lead segments convert down the sales funnel and adapt your performance marketing campaigns accordingly.