How UNNI Reduced TikTok Retargeting CAC by 51.8% with SKAN and Airbridge

Introduction

About UNNI

With a mission to make better medical services accessible to everyone, UNNI is driving innovation in the beauty medical industry by combining transparent healthcare information with a powerful IT platform.

Launched in South Korea, the platform has expanded to Japan, Thailand, and beyond. UNNI supports both international patients seeking treatment in Korea and local users looking for trusted clinics nearby. By focusing on transparency and user needs, the team is building a more consumer-centered approach to medical care. As of 2025, over 7.3 million users have turned to UNNI to confidently find and book aesthetic medical procedures.

Overview

To improve iOS campaign performance under Apple’s App Tracking Transparency (ATT) policy, UNNI restructured its TikTok strategy. While TikTok had been a reliable user acquisition channel, ATT made it harder to track user behavior and optimize performance. With limited access to IDFA, ad platforms struggled to build accurate retargeting lists and train their algorithms effectively. Although TikTok adopted SKAdNetwork (SKAN) for attribution, the data remained delayed, limited, and insufficient for understanding the full user journey.

That’s when UNNI began testing TikTok’s Non-Direct Click (Non-DC) campaign format, supported by Airbridge’s measurement and reporting tools. The goal was to close the gaps left by SKAN and build a smarter, more efficient iOS retargeting strategy.

Challenges

• Securing meaningful user signals and reducing CAC under iOS ATT restrictions
• Boosting TikTok campaign performance on iOS with redesigned campaign structure

Solutions

Driving TikTok Non-DC Retargeting Performance with Airbridge Data

To improve iOS campaign performance under ATT constraints, UNNI launched TikTok’s Non-Direct Click (Non-DC) retargeting campaign using both SKAN data and measurement insights from Airbridge.

Although TikTok’s Non-DC format is typically used for retargeting, UNNI adapted it to optimize for the register event by targeting users likely to become new members. To test effectiveness, the team ran an A/B experiment comparing:

1. A user acquisition campaign measured solely through SKAN
2. A retargeting campaign leveraging both SKAN and MMP (Airbridge) data

The results were clear. The hybrid approach using both SKAN and MMP data outperformed the SKAN-only campaign under the same conditions.

While Non-DC campaigns couldn’t reach users who declined ATT tracking, combining MMP insights with SKAN data gave the team a more complete view of user behavior and enabled smarter targeting. The test confirmed that even within iOS’s privacy constraints, better measurement inputs can lead to more efficient and higher-performing campaign structures.

The campaign delivered a 1.2x higher conversion rate and reduced CPA by 51.8%, with user registration as the primary KPI. Notably, nearly 90% of users who registered were new. Showing that the retargeting strategy was not only re-engaging past visitors but also reaching and converting a large pool of fresh new users.

A key driver of this success was improved visibility into iOS user behavior, powered by Airbridge’s integration with TikTok. As an official measurement partner, Airbridge enabled:

• Advanced SAN integration
• Automated SKAN mapping
• Support for TikTok’s high-engagement conversion metric like Focused View

Results

Apple’s ATT policy has reshaped mobile marketing, creating uncertainty for many teams. UNNI responded by restructuring their strategyand reinforcing their measurement stack.

Their success with TikTok’s Non-DC campaign shows that strong iOS performance is still possible with the right tools. Airbridge helped close the data gaps, giving the team a clearer view across the funnel and enabling more confident, data-driven decisions.