Well if the kit sponsors are only offering a certain amount, and Adidas made the best offer, then what are we supposed to do about it? These things are determined by sales figures.
2016 shirt sales
Man Utd 2.85m
Real Madrid 2.29m
Barcelona 1.98m
Chelsea 1.65m
Bayern 1.5m
Arsenal 1.225
Juventus 0.85m
Liverpool 0.705m
PSG 0.685m
Milan 0.65m
So we sell 30% of the shirts that United do. They currently get £75m p/a from Adidas. We get £20m p/a. So we get 27% of the money they do.
The other thing with a lot of these deals is that clubs get tied in to a certain amount for a period of time. Look at Real Madrid, they get £34m and Barcelona's new one is £100m because it has more recently been negotiated. If we were to renegotiate tomorrow we'd get considerably more.