Gain Theory, A Global Foresight Consultancy

We accelerate growth for ambitious brands

We are a global marketing effectiveness and foresight consultancy. By fusing deep expertise with advanced AI, we empower marketers to make smarter and faster data-informed investments that deliver unmatched value.

Forrester Wave Leader 2026

Gain Theory named a Leader in The Forrester Wave™:

Marketing Measurement and Optimization Services, Q1 2026.

$

26

bn

in client value generated

50

+

years of experience

910

client recommendation score

What we think

Banker discussing with affluent client

Global bank uses MMM to identify 14% incremental income, drive affluent customer growth

View case study

Marketing effectiveness transformation report 2026 cover

Research | 31 March 2026

Gain Theory exposes why most marketing insights are failing to drive growth

AI creative effectiveness woman jumping advert

Research | 31 March 2026

AI is helping marketers to quantify creative impact – as featured in Advertising Week

News | 26 May 2026

Introducing… Marin Southon, Senior Director, Client Success

News | 26 May 2026

Beyond data, analytics: Research reveals the real reasons why marketing insights don’t get actioned

MMM Insights Dashboard

How MMM unlocked $2.8m incremental value for a CPG co in two challenged markets

View case study

Want to know what our industry-leading experts have to say?

Using our award-winning solutions, you can:

Focus on measuring what matters

Increase speed and quality of insights

Create value over the short and long term

Interested in our
award-winning solutions?

Start exploring

Meet our people

Meet our people

Marin Southon

Senior Director, Client Success

Marin shares her journey from leading media strategy to driving business growth through marketing effectiveness, why staying connected to consumers is critical in an era of shrinkflation, and how she and her dog are conquering an agility course one obstacle at a time.