Why SDK Size Matters
App download size directly affects install conversion rates. Research from Google shows that for every 6 MB increase in APK size, install conversion rates drop by approximately 1%. For iOS, Apple's cellular download limit (currently 200 MB) creates a hard threshold that affects users on mobile data.
Every SDK you add to your app contributes to the binary size. Understanding the footprint of affiliate tracking SDKs helps you make informed decisions about your integration approach.
What Contributes to SDK Size
Affiliate tracking SDKs typically include:
- Core attribution logic: Code for capturing and storing attribution data from deep links
- Deep link handling: URL routing, universal link support, and deferred deep linking
- Network layer: HTTP client code for communicating with the attribution server
- Device fingerprinting: Code for collecting device characteristics used in probabilistic matching
- Dependencies: Third-party libraries the SDK relies on
The size of each component varies by SDK and platform.
Typical SDK Size Ranges
Affiliate and attribution SDK sizes generally fall into these ranges:
Lightweight SDKs (under 1 MB): Minimal SDKs that handle basic attribution and deep linking. Insert Affiliate's SDK falls in this category, focusing on core attribution functionality without unnecessary bloat.
Mid-weight SDKs (1 to 5 MB): Full-featured attribution platforms that include analytics, A/B testing, and advanced attribution features alongside basic tracking.
Heavy SDKs (5 to 15 MB): Enterprise-grade platforms with comprehensive feature sets including fraud detection, advanced analytics, multi-touch attribution modelling, and extensive device data collection.
Minimising Size Impact
Choose purpose-built SDKs: Select an SDK that does what you need and nothing more. If you need affiliate tracking, use an affiliate tracking SDK — not a full mobile marketing platform that includes features you will never use.
Use server-side attribution when possible: Some attribution logic can be moved to your server, reducing the client SDK footprint. Insert Affiliate uses server-side attribution for much of its processing, keeping the client SDK lightweight.
Enable code stripping: Both iOS (bitcode and link-time optimisation) and Android (ProGuard/R8) can strip unused code from SDKs during the build process. Ensure your build configuration enables these optimisations.
Monitor SDK updates: SDK sizes can grow with updates as new features are added. Monitor your app's binary size after each SDK update and flag unexpected increases.
The Full Picture
Affiliate tracking SDKs are typically a small fraction of your total app size. For context, common SDK size contributors:
- Analytics SDK: 1 to 5 MB
- Push notification SDK: 1 to 3 MB
- Crash reporting: 1 to 3 MB
- Ad mediation: 5 to 20 MB
- Subscription management (RevenueCat): 1 to 3 MB
- Affiliate tracking: under 1 to 3 MB
The total SDK overhead for a typical subscription app is 10 to 30 MB. Affiliate tracking represents a small portion of this total.
When Size Matters Most
SDK size is most critical for:
- Emerging markets: Users with limited storage and slow connections are more sensitive to download size
- Gaming apps: Already large binaries where every MB counts toward platform limits
- Utility apps: Users expect small, focused utilities — a 50 MB flashlight app loses credibility
For most subscription apps in mainstream categories, a well-optimised affiliate SDK adds negligible impact relative to the revenue opportunity it enables.
Making the Trade-off
The question is not whether the SDK adds size — it does — but whether the revenue generated through affiliate tracking justifies the marginal increase. For subscription apps, even a single affiliate-referred subscriber who stays for a year generates far more value than the theoretical conversion loss from a sub-1 MB size increase.
Insert Affiliate's SDK is designed to minimise binary size impact while providing complete attribution functionality. The lightweight approach means you get accurate affiliate tracking without compromising your app's download conversion rate.