To get this you will need to have facebook.
Go to HUKD and select a deal over 100 degrees. At the bottom of the deal there will a tab labelled "Add to Facebook Hotlist"
When clicking on the link it will ask you to log into facebook. Once you have added 5 deals you should have an Amazon voucher code at the top of the screen. Listed as a chance to win an Amazon voucher, however once you add one to your list it says "add 4 more deals to get an Amazon Voucher"
Just done this for me and my brother.
Hope it helps you out this christmas.
Think also the voucher will work with other vouchers such as the Match stick hunt one as I combined vouchers on my order.
Credit to OP on Moneysavingexpert - Saintscouple