Glossary

Device ID

A device ID is a unique identifier assigned to a single device that apps can use for measurement, personalization, and privacy aware advertising. Examples include Apple ID for Advertisers on iOS and Google Advertising ID on Android. With user permission where required, device IDs help teams attribute installs and in app actions to the right campaign, control frequency, and tailor the first session experience.

Plain language explanation

Think of a device ID as a license plate for a phone or tablet that apps can read. It does not contain a name or email. It is just a coded label that lets the app and its measurement tools know that the same device returned later to complete an action.


Why device IDs matter

Attribution with confidence

Match an install or purchase back to the click or view that drove it.

Personalization that respects consent

Show relevant offers and limit ad fatigue once permission is granted.

Campaign optimization

Shift spend toward sources that create high value users based on real outcomes.

Cleaner analytics

Remove duplicate counts and understand cohorts by device type, region, and app version.


Primary advertising device IDs

IDFA on iOS

The Apple advertising ID is an upper case alphanumeric string. Apps can access it only after the user grants permission through App Tracking Transparency. If the user declines, the app cannot read this ID.

GAID on Android

The Google advertising ID is a lower case alphanumeric string. It can be reset by the user and ad personalization can be limited. Google is evolving Android privacy features, so plan for reduced reliance on this ID over time.

IDFV on iOS

The identifier for vendors is scoped to one developer account across its own apps on the same device. It does not require the tracking prompt and is useful for cross app analytics within a single company.

OAID on select Android distributions

Some device makers provide an anonymous advertising ID when Google services are not present. It can often be reset by the user.


Other device identifiers that are not advertising IDs

Android ID

Created on first boot or factory reset. Intended for system use, not for ads.

App set ID on Android

Helps a developer understand which of their apps are installed on a device without creating a cross app tracking ID.

IMEI

The cellular equipment number used by networks. Not for marketing and must not be used for ads.

UUID or GUID

A generic unique value. Some apps generate their own app scoped identifier for internal use.


How device ID based attribution works

  • A person taps an ad and reaches the store page.
  • They install and open the app.
  • The app SDK records the device ID if available and permitted.
  • The measurement service searches recent clicks or views for a matching record.
  • If found inside the attribution window, credit goes to that source.
  • Downstream events such as sign up or purchase are tied to the same record.

This is called deterministic attribution because the same identifier appears on both sides of the journey.


Privacy landscape and practical guidance

Consent first on iOS

Show a clear value based prompt before the ATT request. Explain how data improves the experience. Respect the choice immediately.

Respect user controls on Android

Honor ad personalization settings and resets. Prepare for Privacy Sandbox signals as GAID access changes.

Data minimization

Collect only what you need, encrypt in transit and at rest, and set retention limits.

Fallbacks

When IDs are not available, rely on aggregate reporting such as SKAdNetwork on iOS, predictive models, and incrementality testing to see lift without personal identifiers.


Best practices

  • Ask for permission only when value is obvious, such as after a clear in app benefit is explained.
  • Cap frequency across campaigns to reduce fatigue on opted in users.
  • Keep separate reporting for user level IDs and aggregate frameworks so results are not mixed.
  • Offer an easy way to reset or opt out, and make the effect of that choice transparent.
  • Monitor match rate, consent rate, and the share of revenue tied to opted in traffic.

Common pitfalls

  • Storing IDs in clear text or forwarding them to vendors without need.
  • Using non advertising identifiers for ads such as IMEI or Android ID.
  • Treating denied permission as a dead end instead of using aggregate measurement.
  • Mixing deterministic and probabilistic results in one metric which hides risk.

How grovs.io helps

Grovs connects consented device IDs to clean attribution, frequency control, and personalization while keeping privacy controls front and center. When IDs are unavailable, Grovs reports through aggregate methods and incrementality so you can steer spend with confidence.


Frequently asked questions

What is a device ID

It is a unique code on a device that apps can read with permission to measure and personalize experiences.

Do device IDs reveal who I am

No. They are anonymous codes. They can link actions on the same device but do not contain personal details.

What is the difference between IDFA and GAID

Both are advertising IDs. IDFA requires user permission on iOS. GAID can be reset and is governed by Android privacy settings.

Can I use IDFV for advertising

Use IDFV for analytics across your own iOS apps. Do not treat it as a cross company ad identifier.

What if permission is not granted

Use aggregate reporting such as SKAdNetwork on iOS and rely on modeled insights and incrementality tests.

Can users reset these IDs

Yes. Both iOS and Android let users reset or limit use of advertising IDs.

Is device ID use legal under privacy laws

Yes when you present clear notice, obtain consent where required, minimize data, and provide user controls.


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