Everything is working fine and I also get the values in GA website. But the problem is when I run the app in marketplace testkit I am getting the error "Pressing back button in "MainPage.xaml" does not close the dialog box".
<Application.ApplicationLifetimeObjects>
<shell:PhoneApplicationService
Launching="Application_Launching" Closing="Application_Closing"
Activated="Application_Activated" Deactivated="Application_Deactivated"/>
<local:AnalyticsService WebPropertyId="UA-1234-1" />
</Application.ApplicationLifetimeObjects>
But When I remove local:AnalyticsService from file its not giving an error.