Various credit cards give you the ability to create per-store cards that can be shut-off or have shutoff dates. When I sign up for a trial now, I use a temporar

Various credit cards give you the ability to create per-store cards that can be shut-off or have shutoff dates. When I sign up for a trial now, I use a temporary card that is locked before the payment kicks in. My card actually has a nice browser extension that automatically gets or generates a per-store card when I hit a payment form. Very convenient.