This is where my head first went when I saw the design brief and you suggested a solution to what I think is the biggest challenge - who pays for these premium cups? I think you have market validation for this approach. In the past, coffee shops offered fair trade coffee to customers for a premium, of say $0.25. At least where I live, which is not particularly representative, fair trade coffee seems to be the standard a premium is no longer required. There might be a similar opportunity for these sorts of cups.
My question is - how do you get people actually plant the cups? Could you have the option for people to purchase the premium cups and then donate them to a community garden all at the same shop?
Interesting idea and I really like how you are working to align incentives for the different business stakeholders. My mind immediately goes towards how the unit economics work for this.
Could you build a simple financial model to identify your assumptions like cost to collect, anticipated fees from coffee shops, purchase price for bulk coffee cups, etc? I think that might help you identify what to focus on when it comes to prototyping.
First, I love the simplicity of the solution. I don't know enough about how different materials get recycled to know if your solution is more sustainable. My questions for you all are: 1) It seems like most chains give all customers single use cups regardless of whether the customer is staying at that location or not. -Is there an opportunity to create something that could be reusable if the customer stayed at that location but recyclable if they left? -Also, why do local coffee shops give glassware for drinks that are for here and disposable cups for those leave, versus everyone getting disposable? 2) I love providing a bit of an incentive to separate the two materials. -How can you get the customer to take the next step and recycle them separately? -Could you do something in store to teach people how to do it?