SKAdNetwork 101: What is it? What does it mean for you?

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What is SKAdNetwork?

SKAdNetwork (StoreKit Ad Network) is a framework, a set of software and protocols created by Apple for privacy-safe mobile attribution for user acquisition campaigns. SKAdNetwork, or SKAN, allows marketers to get deterministic but aggregated attribution of mobile app marketing campaigns. That means marketers know which advertising campaigns worked and what marketing channels are performing, but it’s still privacy-safe: they don’t get device-level data on what individual people are doing.

Apple made SKAdNetwork essentially mandatory for mobile marketers in iOS 14.5 and on.

First, App Tracking Transparency (ATT) required apps to ask permission to access their app users’ IDFAs so they could track ad campaign effectiveness. Then, Apple made it clear that an alternative form of mobile attribution known as fingerprinting — tracking users by following their semi-unique device signatures around the internet — was never kosher: with or without tracking authorization via ATT.

Read on for all the details …

More than 5 years ago, in May 2018, Apple introduced a new concept and API called SKAdNetwork.

That API would allow mobile app install attribution while preserving privacy. At that time, many questions were raised about the future of mobile attribution on iOS and the place of SKAdNetwork in it. But with iOS 14.5, Apple made massive updates to SKAdNetwork and released SKAN 3, the first version that became functionally useful for mobile attribution. The updates to App Tracking on iOS in April of 2021 manifested in the AppTrackingTransparency framework and Apple’s new privacy guidelines.

In 2022, Apple further updated SKAdNetwork with the launch of version 4, commonly referred to as SKAN 4. And at WWDC 2023, Apple announced SKAN 5, which will offer the ability to attribute re-engagements. There are no further details about SKAN 5, however, and we don’t know exactly when it will become available.

SKAN 4 is much more capable than SKAN 3, with several key differences:

  • Privacy thresholds became crowd anonymity, which should reduce null values in install postbacks
  • Campaign IDs became source identifiers, providing more insight into campaigns that work
  • 1 postback became 3 postbacks, offering more insight into quality and cohorts
  • Postbacks became separated into two types: fine and coarse. The first postback can be fine, which  offers 64 different potential values. The second and third postbacks are coarse: 1 of only 4 possible values.
  • Timing changes, with marketers able to lock postbacks when a significant conversion event happens and get earlier data
  • Web-to-app support
  • Conversion values can decrease as well as increase in SKAN 4

(See a full SKAN 3 to SKAN 4 conversion guide right here.)

Singular has been preparing to utilize SKAdNetwork for a long time, and we made those plans a reality very early. We still get many questions from customers and partners who want to learn more, and we’ll continue to update our blog with multiple series to explore how SKAdNetwork works, what kind of data points it provides, and how it can be used for marketing measurement.

In this post, I will try to keep things high level.

What does SKAdNetwork do?

SKAdNetwork is a framework for privacy-preserving mobile install attribution. It aims to help measure conversion rates of app install campaigns (CPI) without compromising users’ identities.

You might be asking yourself how it achieves that and the key to understanding that is that Apple, and as an extension, the App Store itself is serving as a facilitator. The whole attribution process is actually conducted by the App Store and attested by Apple’s servers. It is then disconnected from user identifiers and temporal information and sent off to the network.

Apple iOS 14 Attribution

How does it work?

Simple … (well, not really, but we will try to simplify it)

When an ad is clicked and the store is opened, the publishing app and the network provide it with some basic information such as network, publisher, and campaign ID. The App Store will then send a notification of successful conversion to the network. It will report the attached values alongside a conversion value that can be reported by the advertised app.

That notification will be sent at least 24 hours after the first launch and will be devoid of any device or user identifying information. Additionally, the App Store conducts the process so the advertised app has no knowledge of the original ad and publisher.  In such a way, the network receives an attestation that an install has happened, without tying the install to a specific user, thus preserving privacy.

With SKAN 4, which is still being implemented throughout the adtech ecosystem, marketers can also get a second and a third postback, providing more insight into how installs from certain campaigns are doing over time. The 3 postbacks, however, are not connected via an identifier or any other key: any cohort insights must be modeled.

What to expect when using SKAdNetwork install attribution

First, let’s cover what you get:

  1. Click-through attribution for ads displayed in mobile apps.
  2. Publisher ID of the publishing app, supporting full visibility and transparency into publishers.
  3. Under SKAN 3
    1. Campaign ID which is limited to 100 values and can be used to code any other campaign information (outside of publisher) such as campaign, creative, and placement.
  4. Under SKAN 4
    1. Source identifier which — at high levels of crowd anonymity — can provide 4 digits of information on campaign, creative, ad set, geo, and so on
  5. Under SKAN 3
    1. SKAdNetwork will tell you if this is the first time the user installed the app or not (is it a redownload).
  6. Under SKAN 5 (announced by Apple at WWDC 2023)
    1. SKAdNetwork will add the ability to attribute re-engagements with people who already have your app installed.
  7. Under SKAN 3
    1. Conversion Value, which is a number between 0 and 63 that can be set by the advertiser after a conversion happens, allows basic post-install tracking (for example, it can be used to show the highest level the user got to in the first day of playing). That value’s purpose is to give some estimates to the users’ quality.
  8. Under SKAN 4
    1. The first postback offers the same 0 to 63 number for what is now called a fine conversion value, if you achieve sufficient volume per campaign
    2. Apple has added 2 additional postbacks with conversion payloads that are coarse: 1 of only 3 possible values
  9. Apple’s cryptographic, unforgeable verification of the attribution and parameters. This is important, as it means anyone can verify that an install really happened without compromising user privacy.
  10. Accurate and mostly fraud-free attribution.

Now, to what you don’t get:

  1. View-through attribution wasn’t initially supported, but Apple has since added some limited capability for view-through attribution
  2. Click-through attribution for all ads displayed in a browser, email campaigns, and any other media apart for native ads
    1. Note though, that Apple added support for web-to-app measurement in SKAN 4. It is only for mobile Safari, however, so desktop and Chrome and Firefox and Brave (etc!) are not supported.
  3. Real-time data
    1. Notifications are sent to the network after 24 to 48 hours. Any subsequent update to the conversion value will postpone the notification. (Notifications are sent 24 to 48 hours after the app opened or the latest update to the conversion value). Apple is doing that to deter attempts to tie in the notifications with app activity to identify users.
    2. Under SKAN 4, the second and third postbacks have even longer postponements.
  4. User-level data: notifications do not include user identifiers.
  5. Data on small campaigns or publishers: Apple will send notifications only after a certain amount of conversions happened for the same publisher app and campaign ID. Apple does not publish what the privacy thresholds in SKAN 3 or the crowd anonymity in SKAN 4 levels are, nor does Apple specify how this count is actually being done.
  6. Advanced attribution services such as deferred deeplinking and long cohorts / LTV.
    1. Though you can get these via Singular’s SKAN solution, with some modeling.

Getting the most out of SKAdNetwork as an advertiser

As an advertiser, you must be asking yourself what’s the best way to utilize this mechanism that Apple has created.

Here’s a short checklist of the must-haves:

  1. You’ll need your media partners to support it by correctly integrating with the SKAdNetwork API. You’re mostly covered here for SKAN 3, and the ecosystem is building support for SKAN 4 now. Expect that to be fairly widespread by late summer 2023.
  2. You’ll also need to collect and validate, either yourself or with a vendor, the cryptographically signed install notifications from each and every media partner, in order to identify any issue or misuse. The goal here is to make sure everyone is telling the truth, and no funny business is going on. While we would all like to believe that everyone’s telling the truth, we also know that you can never be too safe, for the same reason that self-reported numbers should not be trusted. (Of course, your MMP — Singular — does all this collecting and validating for you.)
  3. Next up is analytics and reporting, to make sense of it all. The SKAdNetwork API provides a limited set of values and identifiers, which poses a challenge, yet not an impossible one. This is where smart encoding would help you maximize the amount of information you can pass via Apple’s API.
    For example, Campaign IDs can be valuable but must be selected intelligently. You’ll want to ensure that the way that Campaign IDs are assigned is consistent across your channels and is supporting your reporting. (Singular provides super-simple ways to encode SKAN 3 and SKAN 4 campaign and  conversion information.)
  4. Intelligent parameter selection can also make a difference in optimization and post-install measurement. Having only 64 values (represented by 6 bits) for conversion information is limiting, yet a lot of information can be encoded using these 64 values if used smartly. For example, users can be categorized based on first-day activity to create segments that would later get grouped and evaluated for performance. You will need an automated way of assigning and tweaking these values without requiring dedicated Engineering work for it, so you’ll likely want a tool that can manage them, and tie it back to your reports.

Measurement partners such as Singular are well-positioned to support this whole process, starting with media partner integrations and assuming the central role in verification, analytics, and reporting. Here at Singular, we’re pretty confident that we provide the best possible solution for implementing SKAdNetwork, and the above are the foundations we have built into that solution. 

Interestingly, we see this move as a natural progression of Singular’s product.

Singular’s unique position and unique integrations with media partners allow us to make the most out of this new API and enable our customers a fluid, seamless transition into this new age. We will work tirelessly to make sure our customers can utilize all the tools that are available to them.

Join our Mobile Attribution Privacy (MAP) group on Slack to exchange ideas and ask questions about these new privacy measures.

Ad fraud tutorial series: What is click injection?

Digital ad fraud, including click injection, is a growing challenge for mobile app marketers.

Fraudsters are constantly developing new methodologies to deliver fake installs. This series of posts is designed to help app marketers understand the key methodologies for perpetrating mobile ad fraud and how they can detect and defend their businesses against bad actors that would steal digital advertising investment from their brand.

The good news: Singular’s best-in-industry fraud detection suite can catch and eliminate click injection fraud. And we integrate with the Google Play referrer API to make this — and other types of fraud — much harder for the bad guys.

This post is about the challenges that arise from fraudster use of click injection, which is similar to click spamming but not identical.

What is click injection?

The traffic flow for an install is a bit more complicated than for other forms of desirable digital advertising actions. With an install, there are extra steps that need to be considered — steps which provide an opportunity for app ad fraud.

Here’s a brief synopsis of the process in five discrete steps.

  1. A user sees an ad and clicks on it, and is redirected to an app store (either Apple App Store or Google Play.) The ad network records the click and sends information about the time the click occurred to the attribution platform.
  2. The user downloads the app and installs it on their device
  3. The user must then launch the app in order for the install to register with the attribution provider.
  4. When the attribution provider receives the signal of an install, it then examines all of the ad signals it has received from ad networks to determine which network(s) deserve credit for that install. In most cases, credit for the install is awarded to the advertiser that delivered the last click before an install.
  5. If no clicks have been registered, then the install is counted as an organic install, and no credit is awarded to an advertiser.

Note: with self-attribution media sources, there’s an additional step, but it is not relevant to understanding click injection.

While sometimes apps are launched immediately after an install, in other cases there is a delay of minutes, hours or days. This delay provides fraudulent actors with the opportunity to claim credit for an install even though they actually did not drive it.

Innocuous-looking fraud apps

The trick they use to do this is to encourage users to download and install a seemingly innocuous free app. For example, a flashlight or toolbar app. The app can function as advertised, but its real purpose is to perpetrate click injection fraud.

Often such mobile apps originate in third-party Android app stores.

It does this by listening for an “install broadcast” — a signal that an app has been launched for the first time on a device. The signal can include a campaign id, and the attribution provider uses this to determine which media source drove the last click.

When the install broadcast is sent, the app goes into action, informing the attribution provider that they just registered an ad click for the campaign, even though no click has taken place. By timing the fraudulent click to the moment of install, the fraudster ensures that it is the “last click” — it will get credit for the install when the app is actually launched for the first time.

An android phenomenon

Click injection is a type of ad fraud unique to Android, because only Android sends install broadcast messages to the apps on a user’s device at the moment of first launch. That broadcast is necessary to alert the fraudulent app to send a click signal to the attribution provider.

How click injection hurts your data

The clicks that these fraudulent app claim to have occurred never actually occurred. Instead, they falsely claim credit for installs driven by other ad networks. Thus they can significantly distort attributions and through them budget allocations.

Detecting click injection

The primary way that companies detect possibly injected clicks by examining the timing of the reported click versus the first launch. With click injection, the timings are likely very close to one another. With other installs, the timings tend to take place farther apart, and follow a fairly consistent distribution. This pattern recognition is an important part of how companies detect and prevent ad fraud.

Defending your business against all forms of ad fraud

Click injection is one of the many ways that app businesses can be affected by ad fraud. Here are a few strategies to help you detect ad fraud in a variety of forms, and protect your business from the costs of ad fraud.

  • Anti-fraud tools: Some attribution and analytics suites offer tools to help marketers identify and prevent ad fraud. Singular, for example, automatically offers many protections. Such tools often use signals like IP addresses, click and install pattern detection, and activity monitoring to pinpoint campaigns, partners and buying models that are driving suspicious app installs.
  • Common sense: A deal that sounds too good to be true is likely to result in low-quality app installs. Marketers must constantly resist the temptation to sign up for media deals that sound too good to be true.
  • Focusing resources on trusted partners: Most brands spend a great deal of money on installs. It makes sense, then, to focus dollars on partners that you know and trust.
  • Leveraging retention and uninstall data: By comparing the set of user traffic attracted by different media companies, brands can learn a lot about user quality. Low user retention or high uninstall rates increasingly are seen as signals of possible fraudulent activity.
  • Use ROI analytics as a primary KPI: When app publishers measure and optimize to ROI, you get both a true picture of the value of the user traffic that you are driving, and a powerful way to optimize your digital advertising investments.

Even a cursory review of this list reveals that seriously addressing ad fraud on your own, including click injection, requires a significant investment of time and money. That’s one of the reasons why companies look to their attribution and analytics providers to carry much of the water. Fortunately, Singular clients are protected from many of the costs and hassles of ad fraud with an unsurpassed set of fraud detection and prevention capabilities.

Singular and ad fraud

Singular offers an industry-leading fraud solutions that you can learn more about right here. For a capsule summary of some of the steps we take to detect and prevent ad fraud for our clients, read on.

With Singular, app publishers have visibility into ad performance, media investment, and revenue data. That provides unique advantages in detecting and protecting clients from fraud.