A change as drastic as this will raise the question of why? and this in turn will help educate people who aren't aware of the plastic pollution. Coffee cups are non recyclable and single use, a huge waste of resources and huge impact on the environment! I acknowledge that there is the discount incentive when using your own refillable mug which is great, but this isn't advertised or widely known and isn't enough to deter people from using them. A slow phase out of coffee cups gives people the time to purchase there own and to adapt to remebering to bring it with them.