To get the 50% cash back on seller's fee you need to register to:http://www.wepromiseto.co.uk/
of click on Direct link
Alternatively, you can use Quidco.com but you will only get 40% cashback.
This is spam free and free website. They will send you the money either BACS
or Amazon Gift Vouchers. You do not have to pay anything at anytime.
Once registered just login to the website and go to Ebay through their link.