After recently moving house we had a few rooms that needed furnishing and decided to look around. Upon purchasing our sofa from Sofa Workshop we were given what they call a 'Thank You' pack. Inside are a few cards with various offers.
If you refer a friend who purchases from them, you both recieve £50 back for nothing, which is a good deal in itself.
Not only that but there is a discount card for their sister comany New Height who we were planning on purchasing from anyway. Placing an order for £1,600, we were entitled to £150 off our order, which isn't too shabby since we were going to order there regardless.
I'd assume this isn't available online, but a great deal none-the-less! This also works in reverse if you purchase from New Heights first.