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

Research | 26 August 2026

Gain Theory Launches ‘Growth Decoded’ Video Series to Tackle Marketing’s Biggest Growth and Measurement Challenges

News | 26 August 2026

Growth Decoded: How to Choose Marketing Measurement Innovation That Solves Real-world Problems

News | 26 August 2026

Introducing… Daniel Weiss, Partner

How a CPG Leader Used Advanced MMM to Identify $10M in Incremental Profit

View case study

“Best Day of the Year”: How MMM Unlocked £106m in Revenue for a European Retailer

View case study

Research | 30 June 2026

Gain Theory Launches Creative Effectiveness CMO Study: 62% Struggle to Prove the Value of Their Creative 

Report | 30 June 2026

Creative Effectiveness Decoded: The Global CMO Survey

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

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Meet our people

Meet our people

Daniel Weiss

Partner

Daniel discusses the importance of test and learn to decision-making, why he’s excited about the role AI is playing in creative effectiveness, and the similarities between building a successful NFL team and marketing analytics.