Most companies don't like to make it easy for you to cancel their services. Google, on the other hand, puts the quick links front and centre when you create a reminder to cancel a particular service.
This hidden feature of Google Now, as highlighted by Android Police, will put a convenient "Cancel Subscription" button in a reminder. Just say "Remind me to cancel Comcast" and the card does the rest. So far it's been confirmed to work with Amazon Prime, Netflix, Hulu Plus, Comcast, Spotify, even Google's own All Access subscription. Good news if you're trialling one of those service (perhaps with a little VPN assistance).