What is App Deep Linking and How it Can Drive Growth

[Update: As of iOS 9, Apple no longer supports the URI / URL scheme mentioned in the intro below. Branch Metrics provides a great overview of the switch to the new scheme, called Universal Links. Everything else in this post regarding deep linking strategies for growth still applies.]

For the uninitiated, app deep linking is a fancy way to refer to a URL that points to a specific part of an app. It’s analogous to a URL that points to a subfolder of a website. For example, Instagram assigns a deep link to every user’s profile:

This URL scheme for app deep links must be set up by the developer. It won’t work for your app unless you explicitly define the scheme and URLs. Instagram has a number of handy deep links (aka iPhone hooks), which they define in their documentation.

If you’re an iPhone user with an Instagram profile, try visiting this URL from Safari on your iPhone, but use your own username: instagram://user?username=postalpix (replace “postalpix”). Pretty cool, huh? You should be looking at your profile if you have Instagram installed.

App deep links only work when accessed from a mobile device. The page won’t exist if you visit one from a desktop browser. This is important to keep in mind when using deep links for marketing campaigns. More on this later.

Deep linking can serve as an integral part of user experience and growth efforts. Here are some areas where utilizing deep links can be a game changer for optimizing growth and user experience.

1. Push Notifications

By default, push notifications direct the user to the last view they visited in an app. With some additional coding, push notifications can deep link direct to a specific view of the app.

Consider a push notification for a sale on iPhone cases that we run at PostalPix (we sell a bunch of custom photo products in our app). Without deep linking, the recipient would get dumped into whichever view they last visited before closing our app. This could be the main shop view, a different product category, updating their account information, etc.

With deep linking, we can send the recipient directly to the iPhone cases view, regardless of their last action in our app.

This is a no brainer. Sending the user directly to the product on sale can lead to a higher purchase conversion and better user experience. It eliminates the hassle of remembering and searching for the product on sale.

As you can imagine, there are tons of use cases for deep linking push notifications:

A new feature buried deeper in the app.
Shipping notifications that link to the order status page.
Another user’s profile who just liked/followed you.
And countless more…

2. Ad Campaigns

This is probably the most talked about use of deep links these days. It follows the same logic as the example above with push notifications.

Let’s say you’re Zappos and running an ad on Facebook mobile for a specific shoe. You’ll obviously get better purchase conversion if you direct the visitor to the product view of the shoe in the ad vs. dumping them into the main shop page, where they’d have to find the shoe among Zappos’ 1000s of products.

This is another no brainer in the web advertising world, but only a recent development with native mobile apps because of their unique structure (basically native apps have views rather than webpages).

3. Referral Programs

Airbnb wrote a revealing blog post about how they revised the onboarding flow for their referral program on all platforms, including mobile. In their old program, members were given a unique coupon code to give out to friends when they signed up. Both the member and referral would get $25 toward travel if the referral redeemed the code. Pretty standard stuff:

Member emails/texts/tells code to their friend (referral).
Referral downloads Airbnb from App Store.
Referral signs up for an Airbnb account.
Referral books travel and redeems code at checkout.

Notice that the referral goes through the same steps that any other new user would when they sign up for Airbnb (#2 – 3).

In the new program, the Airbnb growth team decided to create an onboarding flow that catered specifically to the referral. Now, the existing member would share a URL that would direct the referral to a personalized landing page inside the Airbnb app after downloading it. Product/growth/ux nerds should be getting giddy right about now.

Airbnb deep linked the referral URLs to these personalized landing pages inside the native app. The personalization part was done with some fancy tech from Yozio.

The new program increased overall bookings by 25% in some markets, which is insane for a mature startup. User signups and bookings from the program itself increased by 300% per day.

As with ad campaigns and push notifications, the key here is that deep linking helped match the experience of the new visitor to their intent, which lifted conversion.

4. Email Campaigns

Email marketing for mobile apps is a pain. You usually have the following considerations:

Is the recipient viewing the email on web or mobile?
If mobile, what type of device? Does the recipient have my app installed on that device?
If web, where does the call to action send the recipient since the desired conversion is inside our mobile app?

Let’s start with the unrealistic assumption that all email recipients are on mobile. In this scenario, it would be beneficial to deep link the CTA to a specific page inside the app. For example, a “Buy Now” button inside a sale email would deep link directly to a page inside the mobile app for the item on sale. The alternative is linking to the app’s App Store URL, where the user would need to tap “open” from the App Store in order to access your app. The deep link option is clearly a better user experience.

The danger here is what happens when recipients view the sale email on desktops. If the CTA with deep link is clicked there, the recipient will see a dead page. Bad news for conversion rates.

There are a number of ways around this, and they all involve being aware of what device the recipient is using before deciding which URL to send them to. You can design the system in house or use a 3rd party tool. I like what URX is doing with their Omnilinks product. If you use Mobile App Tracking for attribution analytics, check out their documentation for setting up Invoke URLs.

5. Pass in Data

Some savvy growth teams are not only deep linking, they’re passing data through the link as well. Aside from the previously mentioned referral program from Airbnb, a prime example of this is Uber’s recent integration with the Google Maps mobile app.

Google Maps users can now choose Uber as a route option under public transit. When tapped, Google Maps deep links to a view within the Uber app that has all of your trip information already filled out.

All that’s left to do inside the Uber app is tap, “Request Uber.” Talk about an incredible UX. I was blown away the first time I saw this.

Passing data with deep linking is fairly advanced and requires a bit of work to set up manually. It’s worth exploring though because of how powerful it can be. Uber’s using it to encourage retention (Google Maps users that already have Uber installed) and drive customer acquisition (Google Maps users that have never heard of Uber).

Luckily, a number of new products are emerging that do the heavy lifting for us, such as URX, Yozio, Branch.io, and Tapstream. You can expect even more in the near future.

1. Push Notifications

2. Ad Campaigns

3. Referral Programs

4. Email Campaigns

5. Pass in Data

More Info on Deep Linking