Fractional CMO
How I work as a fractional CMO
I'm Tristan Gillen, a fractional CMO based in Lisbon. I work part time inside startups and scale-ups as the senior person who owns growth: the go-to-market strategy, the targets, the experiments and the team.
This isn't theory for me. For the last few years most of my working week has been spent in fractional growth roles and consulting projects, across the UK, Europe and the US. Some of it went brilliantly, some of it didn't, and I've kept notes on both!
Trusted by
Where I've done it
Fractional and advisory growth roles I've held, alongside running Growth Division with Tom Dewhurst. It's the same job each time, just a different team: work out what's actually driving growth, then build the process that keeps it going.
- Squadra Fractional CMO, growth coach and mentor Since 2024
- Growth Squared Growth advisor Since 2024
- Startups.com Growth advisor Since 2021
- Breezy Growth marketer and growth advisor Since 2020
- Alpaca Coffee Growth advisor 2022 to 2023
- Growth Division Founding partner, leading growth for clients like Oddbox, SeedLegals, LUX Rewards and Eat Sleep Cycle Since 2019
What it's led to
What I take on
🎯 Go-to-market strategy
Who you sell to, what you say and which channels you use to reach them. Usually the bit founders have been doing on instinct.
📈 Targets you can hit
A North Star metric, growth targets and a monthly rhythm that keeps the whole team accountable to them.
💡 Channel experiments
Every channel gets a hypothesis, a budget and a kill threshold. We scale the winners and stop funding the rest.
🤝 The growth team
What to hire, what to outsource and what to automate, then hiring and coaching the people (or plugging in specialists from Growth Division).
⚙️ Systems and AI
Tracking, CRM, attribution and automation, increasingly with AI in the loop. It's why I'm building GREX.
Who it's for
- Startups with early traction that need a repeatable growth engine
- Founders who are still acting as head of marketing
- Teams that hired a generalist marketer and didn't see the numbers move
- Scaling agencies and service businesses
- Anyone launching into the UK, Europe or the US
How it works
- A free discovery call. 30 minutes on your goals, your numbers and where growth is stuck.
- We agree the scope. Full fractional CMO or a lighter monthly advisory setup, paid in cash, equity or a mix.
- Then we get going. Strategy, targets, team and experiments, with a monthly review against your key growth metrics.
Wondering about budget? Here's what a fractional CMO costs.
What founders say
Tristan has done a superb job here at Oddbox. We now have a fully automated inbound lead capture and conversion process in place, as well as automation tools that save the Oddbox team time every day!
Deepak Ravindran Founder & CEO 
Tristan's ability to help me drive growth for the company has been invaluable. I have a fantastic sounding board in him and he has provided important guidance on our overall business development. Most of all, it's been wonderful having a kind human being on board who aligns with our business values and supports my entrepreneurial journey as a solo founder. I would highly recommend him to anyone seeking guidance on their business growth strategy.
Victoria Halina Poon Founder & CEO 
Working with Tristan and his growth team we've achieved €1m of extra sales in less than 6 months and are generating 4x our monthly revenue. We have achieved massive growth with them. The best thing about working with Growth Division is guaranteed results each month, they just keep delivering. So I highly recommend working with Tristan.
Lee Comerford Co-founder Fractional CMO FAQs
What does a fractional CMO actually do?
A fractional CMO is a senior growth lead who works with your startup part time. For me that means owning the go-to-market strategy, setting the North Star metric and targets, running structured channel experiments, and building the team, tracking and automation that keep it all going. You get CMO-level ownership without hiring a full-time CMO before you're ready.
How is this different from your mentoring?
Mentoring is a free 30-minute session on one specific problem. Fractional CMO work is ongoing and hands-on: I take ownership of growth, work with your team every month and I'm accountable for the numbers.
Can I start with something lighter?
Yes. Some founders start with a monthly advisory setup: a structured call that keeps you accountable to your key growth metrics, advice on growth strategy when you need it and introductions from my network. If it needs to go deeper, we scale it up.
How much does a fractional CMO cost?
In the UK most fractional CMOs charge between £3,000 and £12,000 a month, depending on how many days you need. I've written a full breakdown in my fractional CMO cost guide, and for early-stage startups I can work for cash, equity or a mix.
Do you work with startups outside Portugal?
Yes! I'm based in Lisbon, but most of my work is with startups in the UK, across Europe and in the US. It's mostly remote, with in-person sessions where they're worth it.
What size of company do you work with?
Mostly startups and scale-ups that have some traction and need a repeatable growth engine, plus scaling agencies and service businesses. If you're still pre product-market fit, I'd honestly start with a free mentoring session instead.
New to all this? Start with my guide to what a fractional CMO is, or go back to fractional CMO for startups.