Apple's introduction of iOS 14.5, allowing users to opt out of tracking cookies, marks a pivotal shift in digital advertising, particularly affecting the reliance on third-party cookies for retargeting and conversion tracking. This change has prompted marketers to reconsider traditional practices, as third-party cookies' decline leads to shrinking audiences and reduced ad performance due to inadequate conversion signals. The emerging best practice for advertisers is server-side tracking, which bypasses third-party systems by sending first-party conversion data directly to platforms like Facebook and Google, offering advantages such as enhanced data control and more precise targeting. This method allows advertisers to define quality leads more effectively, leading to improved ad performance, reduced costs, and a focus on high-quality audiences. The transition to server-side tracking requires marketers to gradually implement new strategies, allowing algorithms to learn and optimize over time. Tools like Clearbit Conversions simplify the adoption of server-side tracking by integrating with existing marketing platforms to enhance lead quality and targeting accuracy, ultimately turning the death of cookies into an opportunity for businesses to optimize their advertising approaches and achieve better results.