Hi, I’m Bart Stemkens — a freelance online marketeer with 10 years of experience helping digital teams grow. I plug into startups and scale-ups to turn strategy into weekly execution — across SEO, SEA, paid social, content, CRO and analytics. No fluff. Just structure, speed and clear results.
Let’s have a discovery call — no prep needed. Just show up, tell me where you are, and I’ll see how I can help → schedule discovery call
Not ready to talk? Drop your website and I’ll send you one growth experiment you could run tomorrow → get one free growth experiment
What I do
I work as a freelance online marketer for B2B and B2C teams building digital products — typically 2 to 3 days per week. I plug into your team to take ownership of your growth goals and execute hands-on across the stack: from data to creative, from ads to onboarding. Most of the work I do myself — if something falls outside my scope (and AI can’t help), I bring in trusted specialists.
This is what you can expect:
- Channel strategy & execution (SEO, SEA, Paid Social)
- Landing page experiments & CRO
- Clear dashboards & KPIs
- Tactical campaigns and ongoing testing
For who I do this
Most teams bring me in when:
- They have online marketing running, but no overview — and no system to test, learn and improve.
- They want to grow, but need someone who knows what to do and actually does it.
- Someone left the team, or they’re scaling fast and need senior hands-on support.
I work with SaaS, B2B and B2C companies — as long as there's a strong digital product and the ambition to grow.
You’ll probably get value from working with me if:
- You have something people genuinely want — and can prove it
- You’re ambitious about becoming the best in your space
- You have someone who can show up to a weekly check-in
- You’re open to experiments flopping — as long as we learn fast
Testimonials
“Bart is a multi-skilled professional able to make your business grow. He can handle high levels of complexity, and is pleasant to work with at all times.”
— Rens, CEO @ KIMO“With Bart, you have everything you need to grow and scale—no extra resources required. If you could clone him, you’d leave your competitors in the dust.”
— Sarah, Head of Growth @ Small Improvements“Smart, pragmatic, hard-working, and a great guy to have around. Our intake doubled, and costs were cut in half. Bart takes initiative, makes decisions, and gets things done.”
— Marnix, Proposition Manager @ Nationale-NederlandenClient cases
From zero to 5,000 paying users in 14 months — with 90% trial-to-paid conversion.
150,000 onboarded users in 10 countries, with low CPA and improving D1 retention.
From 3 to 10 franchise offices, while cutting lead costs by 50%
Get in contact
If the testimonials or cases weren’t enough to convince you to schedule a call, I’ve got one last move: send me your website and I’ll reply with one growth experiment you could run tomorrow. Free. No pitch. No strings.
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