Android 15 ships with the Privacy Sandbox on Android, a bundle of APIs that gradually sunsets the Google Advertising ID (GAID) and the “Limit Ad Tracking” switch. Instead, measurement moves to privacy-preserving, short-lived identifiers and on-device reporting. 

New Terminology in Plain English

Seven Beginner-Friendly Tracking Tactics

1. Switch to App Set ID for Same-Developer Insights
   What it does – Lets you see user behaviour across all of your apps without sharing data with anyone else. Great for frequency capping and fraud checks.
   How to start – Call AppSetIdClient.getAppSetInfo once; cache the ID; respect reset signals.
2. Keep Using the Play Install Referrer for Deterministic Install Attribution
   Why it survives – The referrer string is delivered only to the installing app, so it doesn’t violate cross-app privacy.
   Quick start – Add the Play Install Referrer Library, listen for the first launch, and map utm_source, campaign
3. Log First-Party Events with Firebase Analytics (Plus an Optional User ID)
   Good for – Click-through funnels, ad-revenue events, and in-app purchase journeys.
   Tip – If your users sign in, set setUserID once after login to stitch multi-device sessions — just avoid PII.
4. Adopt Attribution Reporting API – Event-Level Reports
   What you get – One row per conversion with coarse conversion values (e.g., “purchase = true”). Ideal for quick ROAS sanity checks.
   Set-up – Register the ad source on click/view, then register a trigger on conversion; Google sends delayed, noise-added JSON back.
5. Unlock Attribution Reporting API – Aggregatable Reports for Revenue Modeling
   What’s different – Higher-fidelity numbers (revenue buckets, SKUs) are summed on-device and encrypted before upload — perfect for LTV curves.
   Key step – Design 128-bit aggregation keys that map to the metrics you care about, then decrypt them server-side.
6. Experiment with Protected Audience API for ID-Less Remarketing
   Use case – “People who added to cart but didn’t buy” without handing a device ID to 20 ad partners.
   Flow – Add users to a custom audience on the device, run the on-device Ad Selection auction, and log the winning impression.
7. Export Firebase to BigQuery for Holistic, Server-Side Attribution
   Why bother – Mix your Firebase event firehose with aggregated Attribution-Reporting data, referrer info, and ad-network spend for MMM dashboards—no GAID needed.
   How – In Firebase Console ➜ Integrations ➜ BigQuery Link, then query the events_* tables.

Final Tips for a Smooth Transition

• Ask for consent early – Even privacy-preserving APIs often require runtime user consent or declaration in your privacy policy.
  
• Version-gate your code – Detect Android 15 (API level 35) and gracefully fall back on GAID pathways for older OSes.
  
• Test in the Beta channel – Google Play offers a Privacy Sandbox testing track; use it to compare GAID vs. token-based reporting side-by-side before the big switch.
  

Android 15 doesn’t end measurement — it just rewires it. Adopting the seven tactics above will keep your attribution stack resilient, compliant, and beginner-friendly long after GAID fades away.