I'm reading the official documentation from android's content providers and I've seen this:
Decide if you need a content provider.
You need to build a content
provider if you want to provide one or more of the following features:
- You want to offer complex data or files to other applications.
- You want to allow users to copy complex data from your app into other
- You want to provide custom search suggestions using the search
- You don't need a provider to use an SQLite database if the
use is entirely within your own application.
Personally, I have been using ContentProviders in all my projects for the last year and a half. They provide good, database independent, data abstraction to access your data. They are very flexible, I even had a play project where one URI pointed to a SharedPreference while all others where for accessing database tables. ContentProviders also allow you to use already built framework infrastructure such as CursorLoaders, for example. Implementing your own from interfaces and abstract classes is not that hard, but it may be time consuming and error prone, being able to just leverage work that's already been tried and tested is a great advantage.
By the way, I remember the same exact question on a post in google+ about 2 weeks ago where Cyril Mottier gave a very good answer. You can read it here.