Source: http://www.businessinsider.com/app-marke...

With app store competition on the rise, generating app installs and acquiring loyal users is getting more expensive, according to new data from app analytics company Fiksu, compiled in the chart below from BI Intelligence.

In May, the cost of generating an app install on iOS and Android grew 56% and 30%, respectively, from one year earlier, according to Fiksu's Cost Per Install (CPI) Index, which measures the total advertising cost app developers incur per app install.

As such, the costs to market an app on iOS and Android have converged. iOS now stands at $1.28 per install and Android at $1.31 per install. CPI on Android peaked at $1.54 in December 2013, while iOS was as low as $0.81 per install in October 2013. 

Holding onto those users after they've installed the app is even more expensive for brands. The cost of acquiring a loyal user among brands actively seeking out these consumers rose to $1.78 in May, according to Fiksu's Cost Per Loyal User Index. Fiksu defines a loyal user as someone who has opened and used an app more than three times. 

That's up almost 34% compared to May 2013, when the index found the cost to acquire a loyal user was down at $1.33.