Free £20 Amazon Voucher with Sun+.
"Have you tried Sun+ yet? Join now for £7.99 and you'll get unlimited access to The Sun online and on your mobile. If you needed any more convincing, we’re offering you a FREE £20 Amazon voucher when you sign up".
Voucher sent within 28 days of signing up but recently they have been much quicker.
- PS - Pay by paypal so you can cancel the subscription via paypal billing. Very simple and risk free.