Vodafone are currently offering £90 cashback with a sim only contract with quidco and others.. This is a rolling one month contract so it can be cancelled at anytime.. It should track and validate within two months so then if you cancel that leaves a clear £60 profit... or keep the contract and have 6 months free... Take out the lowest £15 contract for maximum profit..
I have started this thread because the other one was for a contract with phone.. This is a completely different deal..