Where should persistent data be saved in an Angular app

I'm building an app that requires access to a data set that is fetched by the page that bootstraps the application and saved as a JSON object in a javascript variable in that page... which I obviously have access to from within the app.

The data is used throughout the app for various functionality. Additionally, some of that data is changed an/or new data is added.

Everything I've read states that persistent data like that should be saved in a service or factory, since they are singletons and they can be easily injected into any controller that needs access to it. So I wrote a service with some getter/setter methods that will allow me to grab or change data stored within it.

I'm just wondering what the difference is between storing the data in a service, where I'd do something like this to access it:

$scope.userAddr1 = PersistentData.get('profileData', 'userAddr1');

and continuing to store it in the native JavaScript of the parent/bootstrapping page where I'd do something like this to access it:

$scope.userAddr1 = profileData.userAddr1; 

I can see how storing it in the service would help keep things organized, but are there any other reasons why this is considered to be best practice?