Upgrading used to mean pressing Pay Yearly and being handed to a payment page on another site. The card form is now part of Magpie: pick monthly or yearly, pay, and you are back where you started.
It is the same form Data Removal has been using, so it does the same things — Apple Pay and Google Pay appear on a device that has them, you can switch between monthly and yearly without losing a half-typed card, and a discount code has somewhere to go.
We already know who you are, so there is nothing to fill in but the card. If you came from a feature that had run out of room, paying takes you back to it.
Your card details still go straight to our payment provider and never touch Magpie.