I'm with David B on this. It's win-win for the supermarket and the charity. Sainsburys will be paying for the airtime and RBL getting the benefit. Any ad by Sainsburys would have cost them the same in production costs and airtime. A pity big business can't do anything for charity nowadays without being accused of ulterior motives.
And for Sainsburys it's a big tick in the CSR box on their ISO 9001 self-assessment questionnaire.
I'm an optimist. But I'm an optimist who takes my raincoat - Harold Wilson