Global fashion eyewear brand Gentle Monster, faced the challenge of evolving privacy regulations and a reduced reliance on cookies, which were impacting the accuracy of their ad performance measurement.
As a trendsetter in the industry, Gentle Monster continuously seeks ways to refine its digital marketing strategies and better understand consumer behavior. To address the impact of changing privacy regulations and the diminishing role of cookies, the brand partnered with Jellyfish to find a data-driven solution that would deliver more precise performance insights and support their forward-thinking approach.
The Jellyfish Analytics team implemented a server-based Meta Conversions API (CAPI), reducing data loss from browser-transmitted pixel events and enabling high-quality data collection for improved targeting and measurement accuracy. To evaluate the impact of CAPI, the Jellyfish team carefully monitored Gentle Monster's always-on purchase campaigns, analyzing performance data before and after the CAPI implementation.
“With 3rd-party cookie restrictions limiting targeting, a solution was needed to minimize data loss and improve accuracy for high-engagement users. Implementing the server-based "Conversion API" enhanced data quality, significantly boosting ROAS.”
– Gentle Monster Marketing Manager
The adoption of Meta Conversions API helped Gentle Monster successfully navigate the challenges of a privacy-first digital landscape, driving measurable growth in advertising efficiency:
Increase in Return on Ad spend
Decrease in average CPA (Purchase)
Additional Purchase conversion reported
For years, marketing relied on a "gold standard" of tracking that felt bulletproof. But in 2026, that foundation is cracking. If your data feels "leaky," it’s because it is. Dillan Ramratten, Analytics Director explains why brands aren't just facing a glitch; they are facing a total shift in how measurement works.
Read Article
At Jellyfish, we marked International Women's Day by coming together to talk about leadership, confidence, and the power of support networks. Inspired by the 2026 theme “Give to Gain,” we explored a simple idea: when leaders give their time, advocacy, and encouragement to others, everyone grows.
Read Article
As AI assistants like ChatGPT and Gemini shape how consumers discover brands, marketers must rethink visibility in an AI-driven world. Nick Fettiplace, UK Managing Director features on The FutureWeek Podcast to explore a major shift in marketing: large language models as a new kind of audience.
Read Article
To mark the 25th anniversary of the cult horror franchise, Final Destination returned in 2025 with Final Destination: Bloodlines. Warner Bros partnered with Jellyfish to design a bold, eerie activation designed to reintroduce the saga and tap into Gen Z's taste for twisted thrills.
Read More