Series A Marketing tech companies in London

At Ocean Outdoor, we lead the way in premium large format Digital Out of Home advertising.Our art is turning Spaces into Places through a deep understanding of our environments. We define ourselves by building commercial value from existing Spaces and turning them into high value Places, creating multi-sensory brand experiences with tangible business outcomes for brands and landlord partners alike. We handpick only the busiest and best places for our screens, across 18 of the UK’s top cities to-date. These iconic 'Ask for it by Name®' locations include London's Piccadilly Lights, BFI IMAX, Liverpool Media Wall and Manchester's Printworks SkyLights. Our uniqueness also comes from our networks at scale such as The Grid and The Loop. We are insight led and creatively driven throughout, whether it’s our 10 years of pioneering Neuroscience research or the latest from Ocean Studio and Ocean Labs, such as 3D DeepScreen®. These are the elements that are core to our values and commitment to our clients.

• Series A
• 148 employees
• Founded 2007

The best of humans and AI for your marketing department.Vetted freelance experts. Marketing-native AI. Passionfruit provides both the talent and the tech to scale your operations instantly.Used and loved by the world's leading scale-ups (Series A and above) and enterprises around the world including PepsiCo, MARS, HSBC, ABInBev, L'Oreal, depop, Miro, AG1 and Iceland.

• Series A
• 99 employees
• Founded 2022

Navigator is a Travel Audience Platform that gives advertisers and agencies aggregated access to over 2 billion first-party intent signals from exclusive partnerships with the world's largest airlines and travel brands, activated with precision across premium multi-channel inventory.Its mission is to make travel audience intelligence the most valuable currency in commerce media. Navigator does this by combining deep Travel-native data signals and expertise with managed campaign delivery, clean-room-agnostic measurement and open integrations across major DSPs and agency stacks - making travel audiences relevant, actionable and measurable across the whole of commerce media.Navigator was founded in 2020, is headquartered in London and operates globally to serve advertisers and their media agencies.

• Series A
• 62 employees
• Founded 2020

For more than a decade, we’ve been helping enterprise brands rethink how they grow.Buyapowa designs and runs reward-led customer acquisition and retention programs for regulated industries — telecoms, energy, insurance, financial services and beyond. Our clients include T-Mobile, AXA, Centrica, Vodafone, Vitality, Flutter and many more who operate in complex, high-consideration markets.Most marketing technology was built for retail: fast clicks, light decisions, simple funnels. But regulated industries don’t operate that way. Decisions take time. There are compliance requirements, eligibility rules, cooling-off periods and real financial consequences. Trust isn’t optional — it’s structural.That’s why Buyapowa was built differently.We combine behavioural design, incentive strategy and robust reward infrastructure to help brands activate structured advocacy. Whether it’s referral programs, partner-led growth, reward payout campaigns, influencer mechanics or performance-led sponsorship initiatives, everything we design is built to support careful, compliant, considered decision-making.Our platform is flexible by design — clients can deploy a single solution or integrate multiple layers — but the philosophy is consistent: growth and retention should be driven by trust, not just traffic.In socially influenced categories, referral is no longer a side channel. It is both an acquisition engine and a churn defence mechanism. If you don’t intentionally activate customer advocacy, competitors will benefit from it instead.We help brands formalise what already happens informally: customers recommending businesses they believe in — responsibly, measurably and at scale.

• Series A
• 57 employees
• Founded 2011

illuma is a British AI company, pioneering contextual solutions for enterprise since 2015. Its real-time scaling technology is used by brands and agencies to boost the results of digital ad campaigns. Meanwhile, broadcasters, publishers and online platforms use illuma to organise, classify and categorise their inventory for commercial activation. illuma is committed to sustaining the open web ecosystem through equitable collaborations between ad tech providers and media owners. The company is proudly building industry-first agreements that recognise media owners’ or sell-side intellectual property rights, and in turn, deliver better outcomes for brands and audiences. illuma was founded by publishing experts and computer scientists from Imperial College, UCL and Cambridge University. The company is based in London with additional offices in New York.

• Series A
• 44 employees
• Founded 2015