IDFV: A New Way to Drive Revenue in a Post-ATT World?

As a publisher, you know how important it is to monetize your inventory effectively and efficiently. You also know how challenging it can be to navigate the complex and ever-changing landscape of mobile advertising—especially with recent changes in privacy regulations.

Since the release of iOS 14 and Apple’s App Tracking Transparency (ATT) framework in 2020, iOS traffic has represented a growing monetization challenge for publishers. This update effectively restricted the ability to track user behaviors, specifically of device-level IDFA identifiers, unless users opted into tracking. 

Regardless of these privacy regulations, it remains essential for mobile advertisers and publishers to track iOS traffic on some level. For advertisers, this enables better targeting and advertising outcomes, and for publishers, it drives higher incremental revenue. 

But how is this done in a post-ATT world? One option is IDFV, or Identifier for Vendor, which is a non-personally identifiable signal which can be sent in the bidstream via Supply-Side Platforms (SSPs). 

What is IDFV (Identifier for Vendor)?

IDFV stands for Identifier for Vendor, and it’s a unique identifier that Apple assigns to each app developer on the App Store. 

What makes IDFV unique as an ID is that it’s consistent across all apps from the same vendor on the same device, until a user deletes all the apps from that vendor from their device. If the apps come from different vendors or run on different devices, then different IDFVs are returned. IDFV does not require user consent, and it respects user privacy by not allowing cross-app or cross-device tracking.

While the adoption of IDFV currently varies for different applications, in the cookieless world which is just on the horizon, advertisers are increasingly seeking additional data to run more precise campaigns. This makes IDFV a potentially viable option, meaning sharing it via the bidstream could allow certain publishers to increase revenue as a result.

How does IDFV benefit SSPs?

There are several reasons why an SSP should give serious thought to sending IDFV signals in the bidstream.

Cross-promotional iOS campaigns 

A cross-promotional iOS campaign is a campaign in which an app developer promotes other apps in their portfolio, and thus leverages the same IDFV. 

In this way, cross-promotional campaigns leveraging IDFV will include Limit Ad Tracking (LAT) users (i.e. those who have opted out of tracking) without relying on fingerprinting—which is prohibited by Apple’s App Tracking Transparency (ATT). 

Delivering a way to run this type of campaign is particularly important since the industry is already seeing more and more consolidation as companies build ad networks utilizing first-party data for effective bidding. IDFV enables advertisers and developers to consolidate their users under one brand and target them across applications, all while adhering to privacy restrictions.

Frequency capping

Frequency capping is still a core aspect of trading, but with privacy regulations changing all the time, anonymous data collection will invariably become harder.

Eventually, user agents—i.e. data that contains information about OS, browser, hardware, etc.—will be standardized, containing fewer data signals that can be used for effective identification, which will lead to the need for a new way to perform frequency capping. The answer, as you may have guessed, is IDFVs. Supporting this signal enables SSPs to continue frequency capping as they always have.


Another reason why IDFV is so important is the continued evolution of SKAdNetwork trading in a more constrained environment. SKAdNetwork 4.0 (SKAN 4.0) has been released and it unlocks significant opportunities for building effective bidding logic. By adopting both SKAN 4.0 and IDFV, SSPs can open routes to new ad spend even in privacy-focused environments. 

At the same time, using both specifications gives DSPs additional tools for more precise and granular buying. As discussed above, IDFV unlocks additional cross-promotional options and frequency capping controls, while SKAN 4 gives more flexibility for attribution. Supporting these functionalities on the supply side will serve as a signal to DSPs to buy more of this traffic to support their performance goals—so everybody wins.

Contextual engines and time-driven features

To buy efficiently, bidders will also need better contextual engines and time-driven features, which is where IDFV can help.

IDFV can enhance contextual engines by helping to understand patterns of app usage within a single vendor's suite of apps on a user's device. Although it doesn't provide granular user-level data, it can still provide useful information on user behavior trends that can inform more effective ad placements. 

For instance, if a vendor finds that users often switch between two of their apps, they may opt to show an ad related to the second app when the user is using the first.

Time-driven features refer to patterns in user behavior and ad performance that are related to specific times or time periods. IDFV can help here by allowing advertisers to track when and how often a user is interacting with their suite of apps. Like the contextual engine, even without user-level data, these patterns could provide valuable insights for bidding. 

For example, if a user is found to engage more with a particular app in the evening, it might be more cost-effective to bid for ad space in that app during that time period.

IDFV: Driving incrementality in a post-ATT world

The wheels are already in motion when it comes to IDFV. 

Several big mobile ad exchanges have already started sending IDFV for iOS application traffic. This, in turn, has attracted more advertising spend from sophisticated buyers who are looking for performance-focused iOS supply. This could potentially provide the momentum needed for additional market share and shifting budgets towards more definitive sources.

IDFV is an important identifier for vendors that can help publishers attract more advertising spend from sophisticated buyers. As the industry moves towards a more constrained environment with stricter privacy regulations, IDFV can provide legitimacy and help SSPs maintain the quality of their available supply.

BidSwitch is currently working on multiple initiatives to increase the quality of available iOS supply and we recommend that all of our supply partners consider supporting the IDFV signal for this reason.

If you’re a BidSwitch supply partner and you’d like to know more, reach out to your BidSwitch account manager to assess your traffic and see how IDFV might help you.