First post so be gentle - I think this is a HotUkDeal.
Next - Recommend a friend promotion credits the account of the referrer with £20, £30 and £50 and the referred persons account with £15 each time - on the condition that the referred person spends over £50.
This means that if you find 3 willing friends/family members you can spend £50 on the first purchase and get £35 credit. Spend £50 on a second purchase and get £45. Spend £50 on the third purchase and get £65 credit. Total £145 credit for £150 spend.
Not sure if you can get cash positive by withdrawing the credit from your Next account, but I do know that the £15 credit that the referred person gets is taken off their first £50 spend. I didn't use the free delivery code but this could reduce cost further. We bought lots of stuff from Next Home !!!