I just signed up to this great deal.
I currently pay £10 per month for Spotify Premium, so I get this plus a pair of Beats by Dre headphones worth £75.
When I do the math it works out -
£19 x £12 (contract) = £228
£228 - £120 (Spotify Premium) = £108
£108 - £75 (Beats by Dre) = £33
£33/12 (months) = £2.75
Calculating it this way means the contract works out to be around £2.75 per month, or £33 per year... which is great for me and hopefully you!!