Oh you KNOW it would be a subscription service...

The refills can be purchased directly from the company (for your protection, of course), any unauthorized refills won't have the chip required for the machine to recognize it.

In order to maximize ad revenue (because there's a screen, microphone, AI somehow, and speakers too) your heart rate, pupil movement, credit card score and temperature will be monitored by the system in order to play ads when you are feeling the most receptive.