Sentry removed advertising cookies from their website in July 2023, impacting them both positively and negatively. The removal of cookies has made performance marketing more challenging, with issues including reduced targeting options, increased CPCs, and changes to reporting and attribution models. To mitigate these effects, Sentry shifted towards engagement retargeting on ad channels, relied on UTM parameters and manual bidding for display ads, and prioritized content marketing. They also encountered difficulties in procurement, as many tools struggled to navigate user tracking and cookieless environments. Despite the challenges, Sentry found that going completely cookieless allowed them to gain new insights and perspectives, and they would do it again if given the choice. The future of performance marketing is likely to be cookieless, with companies needing to adapt to new models and tools that respect user privacy.