Admob implementation Error

Question

I got a Problem with implementing Admob into an App.

This is my main.xml:

Answer 1

As you can see here, very few phones have Android versions of 3.x.x or higher installed

http://developer.android.com/resources/dashboard/platform-versions.html

Why would anybody want to compile their app to something few phones can handle? Either I am misunderstanding something or I will need to find some other ad company that doesn't require a newer Android version.