They can sell more. Using their maps? They can sell what kind of places you’re looking up. Using their music app? They sell your listening habits. Have their app on your phone to take calls and texts? They can sell that data (likely not the contents, but the connections and frequency) along with whatever data their app collects about your phone.

On my truck they can sell driving data and the fact that I have an android phone. On their new systems they can sell everything.