95,000 of the roughly 300,000 mobile applications that have ever appeared on the Android Market are no longer available - an app attrition rate of 32%. In comparison, 80,000 apps out of approximately 500,000 (or 16%) created for iOS devices including the iPhone, iPad and iPod Touch have similarly disappeared. This is a notable difference between the two marketplaces, especially given the Android Market's shorter existence.
Why do these numbers matter? For one thing, the app attrition rate is often a factor in calculating store sizes. More broadly, the differences also speak to the opposing cultures of the stores themselves. Many Android developers appear to approach app publishing as an experimental effort, not a business, and publishing and pulling apps far more often than those on the App Store do.
Attrition Not Considered in Recent Reports of App Store Sizes, Growth
This new data comes to us courtesy of Appsfire, a mobile application sharing and discovery service for iPhone and Android. The company recently dispelled reports from analytics firms Distimo and research2guidance, both of which claimed that the Android Market was set to surpass the iTunes App Store in size at some point later this year.
Appsfire says these reports are misleading. At Google I/O, it was announced that the Android Market now has 200,000 apps. Today, Appsfire counts 206,000. But Distimo had found 206,143 back in March, 2011 while research2guidance reported 294,738 apps around the same time. The discrepancy is caused by the firms' failure to take into account app attrition, Appsfire explains, a term referring to the number of apps which are published, then later pulled, from the Android Market.
For comparison purchases, iTunes now has 425,000 apps - over double the number of apps available on Android. Simply put, that means there's no possible way that the Android Market will surpass the iTunes App Store in size any time soon.
Appsfire notes that the other firms may also be counting beta apps or private apps available for Android in their totals. For example, the Amazon appstore app is not listed in the official Android Market. However, if that's the case, then the large number of off-market iOS apps should be counted, too. The jailbreak app store Cydia is available to roughly 5-8% of iOS users, The New York Times reported last winter. With over 200 million iOS devices sold to date according to Apple most recent figures, that's a large number of people with access to these off-market jailbreak apps.
Why App Attrition is Occurring More on Android
Appsfire offers a number of reasons why the Android Market sees a higher app attrition rate versus the App Store (32% vs. 19%). For one, Android developers may see the Market more as a place to experiment with app creation and publishing, given that there's no review process in place before the app goes live. Instead, apps are published immediately and automatically. Google also provides tools like App Inventor that reduce the barrier of entry, allowing even non-developers to experiment with app creation.
Meanwhile, Apple charges developers $100 per year for membership in its developer program, carefully reviews applications and has stricter guidelines in place about what is and is not allowed in the App Store. This leads to less experimental apps for iOS, and therefore, less attrition.
Other reasons for attrition on Android could involve underperforming apps that are pulled and discontinued, apps that don't generate enough revenue and are pulled since they're not worth the effort or investment to maintain, and apps that are pulled because a developer changes course. In some cases, apps may be removed by Google for violating the Terms of Service, but this is less common.
At the end of the day, the big takeaway from this data is that an app store's size is not the only, nor is it necessarily the best way, to track a platform's growth. And this is especially true when stores operate so differently from each other, as iTunes and the Android Market do today.