Quite random this. I went to book a ferry crossing from Holyhead to Dun Laoghaire, and checked in on hotukdeals for offers, codes etc.. Instead found this link in the discussion forum (Kudos to Stainy (http://www.hotukdeals.com/forums/member.php?u=11945) who posted it (http://www.hotukdeals.com/forums/showthread.php?t=41705&highlight=stena))
Example saving is that I just tried to book a late december return ticket on their main site and got a price of £288. I booked it through this and it came up as 306 (That's £209 or so at the moment). Quite some savings.
Sorry, yes, that's 306, Euros :)
In my defence, it seems the Euro symbol is stripped from the posts :)