It's not compulsory but generally Sponsors want the scale of their generosity to be known
When the old rangers company negotiated a new deal for the club which may or may not be the same club as the current Rangers there'd generally be a figure reported.
http://news.bbc.co.uk/sport1/hi/football/scot_prem/8495426.stm
There is of course an incentive for both sides to talk up the deal so the figure is generally expressed as being "up to" some large amount.
People keep telling me I should try online dating so I can meet that special person that a great guy like me deserves to be with. It's beginning to piss me off. My wife on the other hand is already furious
On that subject I reckon Jarlsberg is a hugely underrated cheese for any recipes that involve melted cheese. It goes more gooey than cheddar but tastes more interesting than Mozarella
It may well be that in the olden days giving spectators a roof would have been seen as a frivolous luxury. While in 1995, in the wake of the Taylor Report, Covered seating was seen as something of a necessity.