Most newsagents do not know the margin they make from what I’d call discretionary product – product where counter staff can play a role guiding the customer to one item over another.
I’d recommend yo take a moment to list all of the categories where your staff can guide the outcome of a sale. Next, find out the margin for every possible product in the category. The, check your sales. Finally, work out what you could have made recommending the most financially beneficial product.
Whether you tell staff to recommend based solely on your margin is up to you. At least make that decision with all of the information at your fingertips.
We do that with calling cards, if a customer comes in and asks for a certain card, which has normally disappeared, we refer them to the calling card that has the biggest margin. It’s not a huge profit on a product, but over months will add up auite substantially.