Choose a product you want to push and ask everyone working at the counter on one day to offer it to every customer they talk to and / or serve. get them to record how many times they do this and how many of the item they sell. Compare numbers.
Almost in every situation I have seen, asking for the purchase is enough to achieve a measurable and valuable increase for the business.
This is a challenge because most newsagents don’t want to ‘offer fries’ with the purchase.
I just wish I could get everything in my shop right next to the counter. I have some shelving right next to counter where I put all the pretty new goodies and we sell so much from those shelves. In the quieter time of year when we are not buying a lot of new products we just change various products to this spot and they sell every time. It is such a good spot to talk to customers about the products as you are serving them.