
Siân Allmark - Founder + Marketing & Growth Leader
I'm Siân, I help consumer and tech brands make growth and marketing their core capability.
Thanks for stopping by to see what we're about. If we don't know each other yet, I hope we will over time.
Over the last 14 years, I’ve worked with 50+ high-growth scaleups and global leaders like Samsung, Gousto, L’Oréal, and AB-InBev to design and deliver growth. I’m a DMA award-winner, Google Certified, and Reforge accredited.
Now I do:
- Fractional growth and marketing leadership
- Growth Consulting, rebuilt for Modern Teams
- Go-to-market support for new markets, products, or brands
- Go-to-market and growth at Gousto and AI startup, GitLaw
Every project I work on aims to build in-house capabilities, fuel sustainable growth, and leave a culture where people and performance thrive.
I love chatting all things growth—so come say hi!

At Fifth Mark, our vision is to design the most effective digital growth systems on the planet
With the goal of making digital growth systematic, scientific, ethical, and engaging. As any marketer will know, our work here will never be done. But the journey is one of great adventure, challenge, creativity, and achievement.
In a volatile, turbulent, and ever-changing landscape, we are determined to truly understand growth and to make as much of that information available to our community as possible. This helps us all to deliver more value to our consumers, to our teams, our leaders, and make positive impacts on the environment and people around us.
Our work in designing and delivering growth for consumer brands and tech companies is how we plan to realise this vision.
Siân is not only highly strategic but has a deep operational understanding across the breadth of digital platforms and mediums. This means she ideally placed to inspire and lead teams to deliver at speed but also has the in depth knowledge to challenge, ask difficult questions and ensure the best possible job is done. Siân is an outstanding leader and digital thought leader.



Growth Strategy
Designing Growth
We design growth through our methodology of growth system blueprints. This is a process that allows us to map the total growth system and recommend opportunities and experiments to optimize its component parts.
By mapping the systems and identifying what we call growth modules within them, we gain a unique and deeper view of how businesses have grown and can potentially grow further in the future. From this blueprint, we can then formulate a set of experiments to help us optimize overall performance. We can also implement key initiatives across the non-working parts of the system, such as team structure, brand, and product to increase growth velocity. While this may sound abstract, it is a crucial step in understanding and enhancing business growth.
I would really love to hear your feedback and experiences with your own systems and understand whether these tools help you better comprehend their structure.
Siân is one of the best Growth/Marketing people I've had the privilege to work with. We hired Siân to continue delivery of an existing strategy but she was able to improve what we did in almost every channel in a short period of time - significantly exceeding expectations. She's also a great leader - she was excellent at communicating strategy and results to our team of over 100 people, and also represent Growth/Marketing internally to our various stakeholders. I'd hire Siân again in a heartbeat and recommend her to anyone looking for a growth/marketing leader.



Delivering Growth
Our learning is that designing growth is only half the challenge. Activation is the multiplier. If these best-laid plans never make contact with reality, then they will be worthless. To add to that, as growth professionals, if we ourselves do not actively “grow”, then the quality of our work will falter. That's why we also run our own Growth Marketing team here at Fifth Mark.
It can be challenging to do so as external partners, but we strive to take an integrated and holistic approach. Essentially, this means mixing together key digital channels across paid search, paid social, onsite optimisation, CRM, and organic to create optimal outcomes. This allows us a unique point of view on the work that we do, where we can truly move the budget and focus around for the client's interest rather than being confined to the channels for which we are appointed.
Working with Siân and her team was a real game changer for Camden Town Brewery. Her knowledge of digital is unparalleled and she is fantastic at taking a holistic view of your total business. The progress we made in such a short space of time was incredible to see and went beyond our expectations. The insights we gained from the data analysis helped inform our strategy going forward.Siân gave us the foundations we needed for success, which we still use to this day. But maybe the best thing about working with Siân is that she is an absolute delight. She was so supportive through the whole project and beyond. The entire team benefited from working and learning from her, and enjoyed it immensely.


Never has there been a more challenging time to grow a business.
Never have we needed to all come together to really understand how best to achieve this. Our purpose here at Fifth Mark is to help each and every one of our partners exceed their growth potential whilst creating exceptional value for our community.
However, the future also holds great potential. One of the most exciting projects that I'm currently working on is the creation of our machine learning and AI-driven growth platform. If this is a project you're interested in learning more about or collaborating on, please reach out.
Growth is easier and more effective together, so don't be a stranger. Sign up to our email community to stay ahead with our latest thoughts, strategies, and tactics for growth. I hope to see you around here again soon.
Siân is an extremely competent and professional digital marketing strategist. She really understands the dynamics of working with high-growth startups. Siân was very helpful in defining successful marketing channels for our startups, understanding key metrics and achieving traction channels at the early stage of the company.
