impact.com TrueLink

Our mobile deep linking solution, TrueLink™, sends users directly to the desired place in-app and seamlessly falls back to mobile web. In addition, it layers more advanced features like custom routing rules, interstitials, deferred deep linking, and A/B testing (beta). This guide aims to introduce you, the partner, and your development team to these concepts and provide guidance on how to integrate a brand’s tracking links in a variety of app-to-app scenarios.

Understanding How TrueLink Works

TrueLink and Universal Links (iOS)/App Links (Android)

impact.com’s TrueLink solution leverages Universal Links in iOS and App Links in Android to route the user to a destination in the app or the mobile web page.

Both Universal Links and App Links work in a similar way. The routing decision happens on the operating system level and is highly reliable as it doesn’t require JavaScript fallbacks that may interrupt the user’s journey.

For this technique to work, impact.com works with brands to implement, test, and validate two primary components:

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Intent Filters and Domain Entitlement updates

The brand needs to deploy the app and users need to upgrade to the latest version for Intent Filters and Domain Entitlement to take effect.

Once configured, the user is seamlessly routed to the app or mobile web depending on whether the app is installed or not.

Benefits of Universal Links

It’s worth understanding the benefits of Universal Links in iOS, which are similar to App Links on Android. It’s important to note that alternative techniques like Custom URL Schemes are not officially supported by Apple, and despite being widely used, have certain drawbacks.

The below section is adopted from [Apple’s Support Universal Links] (https://developer.apple.com/library/archive/documentation/General/Conceptual/AppSearch/UniversalLinks.html).

Universal links give you several key benefits that you don’t get when you use custom URL schemes:

Getting Started with App-to-App Tracking via TrueLink

As a partner, getting started with TrueLink for app-to-app tracking requires a few implementation steps. Below are the high-level steps, followed with more detail on each one.

The below steps go into more detail and describe some of the advanced setup capabilities of TrueLink. It’s important to note that many of these capabilities are not required and the best setup is often already the default for many partners. This in-depth review is geared towards better understanding the fundamentals of the system and modern ways of linking content across apps.

Step 1: Acquire and Customize an impact.com Tracking Link

Understanding impact.com’s Tracking URL Structure

The tracking URL is at the core of tracking a click on both desktop and mobile (web and app), and correctly routing the user to the desired web or app destination. The below diagram describes the various components of the tracking URL.

In some cases, partners can also get a vanity tracking URL. This is a shorter link that encodes all of the above information in the pathname (e.g. /bestpartner), which is customizable by the partner.

Tracking Link Query String Parameters

The following optional parameters are supported and can be added to the tracking link. We recommend that mobile app partners pass googleaid and appleifa when available from the native app environment.

Force Mobile Web Experience Through Tracking Link (App Not Installed)

Sometimes you may want to force a mobile web experience using the tracking link instead of routing to an App Install Interstitial or sending the user to the app store. To do this, pass the  force_mweb=1  parameter in the query string of the tracking link e.g. goto.company.com/c/98765/67890/1234?force_mweb=1 . This only works when the brand’s app is not installed.

When deep linking is configured via either Universal Links (iOS) or App Links (Android) and the app is installed, there is currently no supported method to force a mobile web experience.

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Forcing mobile web tracking when the brand app is installed

A workaround of forcing the user to use mobile web when the brand’s app is installed can lead to loss of attribution. For example, if you force the tracking link from the app environment into a webview and the brand has Universal Links or App Links configured on their domains, further navigation by the user inside the webview can lead to a user redirect to the brand’s app. Since the user will be redirected by the brand link and not impact.com’s tracking link, loss of attribution will occur. We would therefore recommend only implementing one of the below partner integration scenarios.

Step 2: Select the Best Integration Scenario for Your App

It’s useful to discuss a few common partner integrations. The two most common scenarios vary based on whether you want the user to be redirected to a mobile browser or a WebView.

Routing the User to a Mobile Browser or the Brand’s App

This is the recommended scenario for most partners. In this scenario, the tracking link can be either loaded inside of your:

The key is that the user click is recognized by the operating system as a user-instantiated click. This means that if the brand’s app is installed, the tracking link will be handled with the Universal Link/App Link setup and fallback gracefully to mobile web in both iOS and Android.

The user flow in this scenario is described in more detail below:

1. User clicks on a link displayed in a WebView within the partner’s app or a button that redirects the user to the browser.

2. If the app is installed, the operating system redirects the user to the brand’s app.

• The brand’s app extracts the deep link configured in the asset or passed by the partner in the “u=” parameter.

3. If the app is not installed, the brand may optionally choose to display an app install interstitial. The interstitial offers the user the option to download the app or continue to mobile web.

• If the user chooses to download the app, they will be redirected to the relevant app store.
• If the user chooses to continue, they will be redirected to the deep link in mobile web.

4. If the user opens the app following a download, impact.com will correlate the referring click and resulting install. Future in-app conversions are attributed as configured by the brand (usually based on a last-click methodology), which is either the click that resulted in an install (3a) or a click from a different partner. If deferred deep linking is enabled, the user will be redirected to the intended content in the app.

Routing the User to a WebView or the Brand’s App (iOS)

This scenario is only recommended if you prefer the user to remain in your app, instead of redirecting them to a browser.

In this scenario, the tracking link is loaded in the native app environment. However, some methods of opening the link from the native environment are not recognized as user instantiated clicks. For example, opening a webview will not result in the link being handled correctly as noted by Apple.

If you want to still use Universal Links, but fall back to a WebView, we recommend the following flow to handle this scenario:

1. User clicks on a button loaded in the native app environment

2. Check if the brand app is already installed on the device. There are two options for performing the check:

• Try to open the tracking link as a Universal Link first. This is the best option when the tracking link is configured with Universal Links. See UI Application Open URL Option Universal Links Only and this example.

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Note

This method will not work when the tracking domain isn’t configured for Universal Links. See Troubleshooting Universal Links in App-to-App Tracking.

• Using the brand’s custom URI scheme registered by the brand’s app (E.g. company://). We recommend confirming the exact URI scheme with the brand. Also, see the canOpenURL method.

3. Route the user accordingly:

• If you are using the first point in step 2, the user will be automatically routed to the brand app. With the second point in step 2, you would be able to use OpenURL to open the brand app.
• If the app is not installed, you can open a WebView to continue within the partner app.

Step 3: Test the User Flow

Once configured and live, we recommend testing the user flow when:

If any of these steps, when applicable, result in failure, we recommend further troubleshooting of the setup based on this guide. If you need any assistance, please reach out to our support team.

Understanding User Routing in the Mobile App

Once the app and domain are associated, the brand configures routing within the app.

The tracking link follows the structure from the below example, where the value of the deep link is contained in the “u=” parameter. The brand’s mobile app development team uses this value to route the user to the appropriate destination in-app. Most commonly, the brand extracts the deep link from the tracking link:

Example tracking link:
https://goto.company.com/c/98765/67890/1234?u=https%3A%2F%2Fadv.co%2Fpromo

Extracted deep link value:
https://adv.co/promo

Once extracted, the brand determines how to handle the deep link in the app.

Understanding User Routing to an App Store

impact.com’s tracking servers parse the browser’s user agent to determine if the user click comes from an iOS or Android device. The user is then routed to the corresponding app store based on their operating system.

Asset Setup

Brands are able to control the routing of the users by implementing several asset-level configurations. Each asset may have different behavior and is important for partners to obtain an asset with the desired configuration. Also, see Understanding impact.com’s Tracking URL for where the asset id is passed.

Mobile App Setup

The Mobile Apps settings allow brands to configure the app’s details, including the Download URL. The Download URL will determine which app the user is routed to when being routed to the app store. The Download URL can be either a direct link to the app store (e.g. https://apps.apple.com/us/app/google-chrome/id535886823) or a redirect through a Mobile Measurement Partner (MMP) to the app store (e.g. https://mmp.link/535886823). The latter allows the MMP to capture any relevant tracking information and facilitate deferred deep linking.

Mobile App Install Interstitial

A mobile interstitial is configured by the brand. The brand can configure the same mobile interstitial for all traffic, or a different interstitial for certain partners. As illustrated in the sample interstitial below, it allows the user to choose whether to download the app or continue to the mobile web destination.

How impact.com Tracks and Attributes In-App Events

So far we’ve been concerned with routing of the user into the app. Correct routing is crucial as it determines whether impact.com will be able to track and correctly attribute credit referral events. For this section, we want to include a brief discussion on how this tracking and attribution works.

Click Event Tracking Methodologies

impact.com uses two primary methods for capturing click events:

Conversion Event Tracking Methodologies

impact.com uses two primary methods for capturing in-app conversion events:

Attribution Methodologies

impact.com uses a combination of methodologies to correlate the referral click and any subsequent events and ultimately attribute credit for an in-app event. This section describes how correlation works for installs and app opens, as well as subsequent in-app events.

App Install Correlation

impact.com will use a probabilistic methodology to correlate the click and install events on iOS devices and a combination of probabilistic and deterministic methodologies on Android. An install is typically reported on the first app open. The probabilistic methodology relies on the click’s connection and browser characteristics matching between the click and install within a short period of time (typically 30 minutes). On Android devices, we also use a deterministic methodology when the brand sends the Google Play Install Referrer.

Once a click and install is correlated, future in-app events are also correlated to the click that generated the install. This works in a similar way as when an app is opened from a tracking link as explained in the following section.

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Tracking through Mobile Measurement Partners (MMP’s)

The brand can integrate natively through impact.com or via an MMP. In the latter case, impact.com will redirect the user through the MMP’s tracking link. An install is then typically tracked and correlated by the MMP, which reports the correlated event to impact.com. In such a case, impact.com relies on the MMP’s attribution methodologies.

App Open Correlation

Once the brand app is launched from a tracking link, a click is reported from within the brand app. The data passed in the tracking link helps us associate the click with your partner id. In this call, brands also pass a set of app-specific first-party identifiers, which allow us to identify the user within the app. This includes a CustomProfileId parameter that allows impact.com to correlate the click with any subsequent app events (subscription, purchase, etc.).

Cross-Device Correlation

Some brands also pass a customer identifier (e.g. a UserId) with impact.com, which is consistent across their app and web properties. This means that if the user opens the app and then goes on to complete a transaction on the brand’s website using a different browser or device, impact.com will be able to correlate the transaction cross-device.

This is a further benefit of sending users directly to the brand’s app because the user is likely to already have an authenticated session. Such app referral creates a more permanent association between the click and future transactions and increases the accuracy of the correlation.

Deferred Deep Linking

Deep linking is the process of sending a user “deep” into an app – that is, to a page other than the default home page. Normal deep linking requires the app to already be installed. Deferred deep linking is the process of “deferring” that deep linking until after a user has installed the app. In this scenario, the user clicks a deep link, is taken to the app store, downloads the app, and is then taken directly to the content they originally wanted to see.

The brand sets up deferred deep linking. Whereas impact.com offers a deferred deep linking solution, some brands may utilize another partner instead.

Generally deferred deep linking works by redirecting the user through the URL of the provider performing the deferred deep linking (remember, this can be impact.com or another party) to the app store. Using this redirect, the provider is able to capture and set certain information, which can be retrieved once the user opens the app at a later time.

For impact.com’s deferred deep linking solution, we support both probabilistic and determining identifiers. Below is an example user flow that describes how the process works:

Troubleshooting Universal Links in App-to-App Tracking

Universal Links are validated on the operating system (OS) level and require a user-initialized action, such as a click on a web link, to open the mobile app.

{
   "applinks":{
      "apps":[
      ],
      "details":[
         {
            "appID":"A1AAA22BBB.com.brand.brand",
            "paths":[
               "NOT /section/*",
               "/item/*"
            ]
         }
      ]
   }
}

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Opening Universal Links in a WebView

If you instantiate an SFSafariViewController, WKWebView, or UIWebView object to handle a Universal Link, iOS opens your website in Safari instead of opening your app. However, if the user taps a Universal Link from within an embedded SFSafariViewController, WKWebView, or UIWebView object, iOS opens your app.

• Original source: https://developer.apple.com/library/archive/documentation/General/Conceptual/AppSearch/UniversalLinks.html