9 April 2026

Reach Announcement

System1 Group PLC (AIM: SYS1)

("System1", or "the Company", or "the Group")

System1 launches next evolution of its Test Your Ad platform

Leveraging AI and Human insight to offer most predictive creative measurement suite

System1 www.system1group.com the marketing decision-making platform is pleased to announce the next phase of its creative measurement tool, Test Your Ad, combining proven consumer-based measurement with smarter diagnostics, more intuitive reporting, award-winning thought leadership and new AI-enabled capabilities. Together, these help marketers understand not just how an ad is likely to perform, but why, and what to do next.

This month, System1 introduces Instant Insights to Test Your Ad reports. These AI-assisted executive summary pop-ups allow marketers to quickly move from insight to action. Rather than users interpreting every chart and metric themselves, Instant Insights surfaces what matters and explains the significance of results. It also shares evidence from System1's extensive thought leadership library, including Orlando Wood's publications Lemon and Look out, The Creative Dividend with Effie and The Long & the Short (Form) of It with TikTok.

System1 is currently beta testing a predictive AI creative measurement tool in select markets which has been trained against its Test Your Ad Competitive Edge database, the world's largest database of emotional norms. The tool accurately estimates the likely human emotional response and distinctiveness response to advertising.

James Gregory, CEO of System1 commented: "We set out a clear plan to enhance and expand our market-leading Test Your Ad platform, as part of our commitment to innovation and product leadership, and we are delivering exactly as promised. This evolution of the platform ensures Test Your Ad remains the most useful and predictive creative measurement tool in the market - combining proven human response, smart and fast AI-powered interpretation and ongoing enhancements to help marketers make better and more confident creative decisions."

System1 has also rolled out additional improvements for Test Your Ad, making reports more insightful, usable and shareable with non-marketers in the business. These include:

·    Second-by-Second Reasons for Emotion, linking scenes in an ad to consumer verbatims to help marketers visualize how people are feeling moment by moment

·    Distinctive Brand Assets, showing which brand assets are being noticed and remembered

·    Key Metric Demographics, helping teams understand how creative lands across different demographic groups

·    Glide Navigation, enabling smoother report browsing and easier sharing across teams

For further information, please contact:

About System1 Group plc

System1 is a marketing decision-making platform business, utilised by some of the world's largest brands, across 81 markets globally. Since 2000, System1 has helped marketers tap into consumers' emotions to predict and improve the commercial impact of ads and ideas. Drawing on the world's largest database of emotional norms, our advertising and idea tests measure emotion to give our customers the most accurate predictions of the business impact of creativity. We 'predict' (provide research results) and work with our customers and 'improve' (provide insight and consultancy on those results) advertising effectiveness, innovation effectiveness and brand effectiveness. 

We work for more than 500 customers, including 5 of the top 10 US and 8 of the top 10 UK advertisers. Customers include Pfizer, Amazon, TikTok, Sky, Lego, Pladis and Natura.

Further information on the Company can be found at www.system1group.com.

About Reach announcements

This is a Reach announcement and the information contained is not considered to be material or to have a significant impact on management's expectations of the Company's performance. Reach is an investor communication service aimed at assisting listed and unlisted (including AIM quoted) companies to distribute non-regulatory news releases into the public domain. Information required to be notified under the AIM Rules for Companies, Market Abuse Regulation or other regulation would be disseminated as an RNS regulatory announcement and not on Reach.