Total sales will be estimated at 25m, but profit margins will be low after staff, food and other operating costs. The catering contractor will either be paid a fixed management fee (club keep all profit) or will share profit with the club. If no profit is generated then obviously costs are too...
Total revenue will be expected to be 25m over the contract period, the caterer will recover costs and will be paid a management fee and the club will keep profit. If no profit is made then the caterer isn't performing and the contract would be cancelled ( as happened last season I suspect).