Last week I tweeted that Pret was considering increasing its discount from 25p to 50p for any customer bringing a reusable cup. We are thinking of doing this to help change habits. It’s well known that “reduce” is better than “recycle”.

How do we encourage more customers to bring reusable coffee cups to @Pret? We’re thinking of increasing the discount for bringing your own cup from 25p to 50p. Our organic filter coffee would cost just 49p! I’d love to hear your thoughts.

— Clive Schlee (@Cliveschlee) November 27, 2017

I was inundated with suggestions, ideas and feedback. All of them were constructive and the vast majority were supportive. Here are five highlights:

1. 96% of the 5,000 respondents on an Instagram Stories poll voted “yes” to the 50p idea.

2. A great many customers recommended that we sell a branded reusable cup as well as launching the new discount. Many shared views on what makes a good reusable cup - light, leak proof and elegant are key attributes.

3. Lots of you suggested we turn the discount on its head and charge for cups instead. The economic theory of loss aversion was mentioned – this says that people respond to loss or fear of a penalty much more than they do to a reward or discount. The success of the government's 5p bag charge was cited as evidence of how effective this can be.

4. A handful of people pointed out that china cups ought to be available in more of our shops.

5. It was suggested that we set up a loyalty scheme tied to reusable cups. Some wanted us to implant chips into the cups themselves that could measure usage and automatically apply a discount.

And one tweeter wanted to see a little less consultation and a bit more action…!

Stop messing about on twitter then and get it done.

— TARSAN (@TARS1981) November 28, 2017

On the basis of this valuable feedback, Pret is going to do three things:

1. Launch the 50p discount in the first week of 2018.

2. Source a well-designed reusable cup, ready to launch later in 2018.

3. Explore adding china cups to more of our shops with seats.

We debated whether charging people for using paper cups felt right. We decided that it goes against our instincts as we would prefer to be generous to our customers than to tax them. Let’s see what impact the new discount has…

Thank you for helping us move forwards!