How to Lower iOS CPI With Conversion APIs

To effectively use a Conversion API, you must send as much information as possible about converting users back to the ad platform. This is where SKAN creates friction. SKAdNetwork (SKAN) provides attribution data to advertisers on iOS so they can measure and optimize campaigns—but the data is severely limited:

• Numbers: For attribution, SKAN only returns a numeric value (0–64) to the advertiser. These values are grouped into coarse categories (low, medium, high), with a maximum of three postbacks per campaign. There is no direct user-level information. Marketers must decide what each value represents and use the limited callbacks strategically.
• Random Timing: Attribution is returned on a delayed timer, typically 24 to 48 hours after a conversion occurs. This delay makes it impossible to reliably associate a conversion with a specific user journey.

With SKAN, you can tell which campaign performs better—but you cannot see who converted or how they interacted with your website or ads. Without user-level signals, Conversion APIs cannot be trained effectively.

Why Fingerprinting Isn’t an Option (Inside Apps)

Techniques like fingerprinting can identify users by collecting device and environment signals (operating system, screen size, time, etc.) through tracking links. When a user installs your game, this data can theoretically be matched and sent back to a Conversion API.

However, Apple explicitly forbids this—even if the user consents:

“Some APIs that your app uses to deliver its core functionality—whether written by you or included in a third-party SDK—have the potential of being misused to access device signals to try to identify the device or user, also known as fingerprinting. Regardless of whether a user gives your app permission to track, fingerprinting is not allowed.”

As a result, while SKAN can help determine which campaigns or creatives perform best (depending on how you interpret callback values), it lacks the depth of data needed to train ad platform AI. If SKAN doesn’t provide enough data and fingerprinting is forbidden inside Apple apps, the question becomes:

How do you train Conversion APIs at all?

Setting Up Two Campaigns

The solution is to set up two separate campaigns:

1. App Install Campaign: This campaign focuses on installs and relies on SKAN for attribution.
2. Landing Page Campaign: This campaign directs traffic to a specialized landing page.

Your landing page must comply with regional privacy laws. If you need a refresher, refer to the relevant privacy lesson. Remember: the United States is generally auto opt-in, while regions like the EU require explicit consent. We recommend using multiple landing pages that are region-compliant.

The Purpose of the Landing Page

This landing page serves two core functions:

1. Cookie / Fingerprinting: Because this interaction happens outside of Apple’s app ecosystem, you can legally cookie and fingerprint users without violating Apple’s Terms of Service.
2. Pixel Event Creation: This is your first Conversion API event. The page should have a single CTA, such as “Download on the App Store.” When users click this CTA, you send a conversion event back to the ad platform signaling high install intent.

By optimizing for this CTA, you can train Conversion APIs to find users who intend to install your game.