The shared factory for user data was created.

Promises work in an asynchronous way, so returning a value from inside a promise won't return that value for a calling function, unless it's inside a callback. Here you should use the callback, which you can invoke with the `then` or `error` methods:

```javascript
usersFactory.addUser(userData).then(function() {
    // everything went fine!
    $scope.users.push(userData);
}).error(function(error) {
    // something went wrong!
    // show an error message
});
```