Rockrose - your choice. I just think it's a service the supermarkets should offer free of charge.
Incidentally, it's not a service I would ever use as I like to choose my own goods.
if paying by card.. you can pay a bit extra for shopping or a product (for example ten pounds) but then they give you ten pounds cash immediately with your receipt. The receipt will say on it "cash back - ten pounds" along with the other receipt usuals.
I certainly appreciate that the delivery service is convenient, or even essential for some; I just feel it should be free as a benefit to customers. It would be absorbed into the cost of goods so, as a non-user of the service, I would be subsidising those who do. My loss.
The supermarkets are a business - they are providing an optional service at a cost, therefore those that choose not to use don't pay for it.
I use it because it delivers all my heavy pet food and whilst I am getting over complications of surgery I am unable to lift heavy goods.
My brother also delivered fruit/veg by bike. Doubt if the shop charged for delivery back in the day. If I want a newspaper delivered by my local shop there is a delivery charge which I assume goes towards the paper laddie's wages.