Why is a special file used in Android to store installation id instead of SharedPreferences?
<p>I am trying to figure out the best way to store my application key and other application specific data. Android uses a file to do it - <a href="http://android-developers.blogspot.com/2011/03/identifying-app-installations.html" rel="nofollow">http://android-developers.blogspot.com/2011/03/identifying-app-installations.html</a></p>

<p>I found that using SharedPreferences is faster and more efficient. Why does Android use a dedicated file just to store the installation ID instead of using preferences? Both require the application context, so that is not a reason.</p>
