When I click on an email link from my iPhone, and the link points to a website that is also a mobile app, and I have the mobile app installed already, why do I get a mobile web page that says "We have an app! Download it here!" instead of just opening the app?

Most Mobile Apps Don't Use Deeplinks When you click on a link from a company whose app you have installed on your phone and it takes you to the mobile web instead of the app itself this is due to the fact that that company either doesn't have deeplinking enabled or the app is using http:// rather than app:// as their link URL. Or both. The Difference Between http:// and app:// For example a company like Airbnb has deeplinking enabled but if you were to go to https://www.airbnb.com/rooms/1341150 from your mobile device and you had the app installed it would still take you to the mobile web. Alternatively if you opened airbnb://rooms/1341150 from your mobile device it would open the app on your phone. The problem with this is you have two separate links for two distinctly different use cases. If you tried opening the airbnb:// link on the desktop web you would get an error (or a google search). How to Create a Custom Deeplink At URX we decided to build a deeplink creation service that combines the two link formats, HTTP:// and APP:// into one link that can be used in any context. The link takes users into the app if they are on mobile and have the app installed and fallback to the mobile/desktop web if they don't have the app or are not on a mobile device. You can play around with creating links at http://goo.gl/izrTB This is a post we wrote breaking down deeplinking if anyone is interested in learning more about it!

That experience frustrates me as well.  Linkedin is the one that personally comes to mind -- I get emails from them all the time from people wanting to connect. When I click from my mobile phone they take me to the mobile site prompting me to login.  I never use the mobile site because I have the app.  And even worse, when I'm on my iPad, they take me to an interstitial asking me to download their app.  Again, I've had the app for nearly 2 years. Unfortunately, there isn't anything you can do as a consumer in terms of altering settings to fix the problem.  However, the companies you do business with can fix it for you. Deep linking to an app is not difficult.  The difficulty lies in detecting if the app exists on the device.  Most marketers want to use one link for their marketing efforts.  And because every device has a browser, a link that points to a website will always "work".  However, as you point out, it's not the ideal experience.  On mobile, you need intelligent links that do more than simply redirect you to a website. SPARQ (http://www.sparq.it) has a platform that allows you to build intelligent links that handle this issue across both iOS and Android.  A SPARQ Link first detects the device and if the user is on mobile and has your app, then the app is invoked and the user is taken into the app experience.  If the app is configured for "deep-linking" like Ebay or Etsy, then you can be taken to a specific product page. If the the user is on mobile but doesn't have the app, then the marketer gets to choose the desired experience.  Either take them to the appropriate app store for install or to the mobile website.  If the user is on desktop, then do what you always do and deep link them to the right page on the website. Here's a useful doc (http://sparq.it/quora) we wrote describing how to enable deep-linking. Hope this is helpful.