This company has been making great sales over the years and introducing a totally new idea for cups could weird their customers out. My idea is based on simplicity.

1. Use recycling paper cups to serve different varieties of cold coffee.
2. Keeping certain reminders in Starbucks that consumption of non recycled cups are causing environmental problem would obviously get their customers to think and maybe concerned about the fact.
3. Put notices in Starbucks which says " bring your own cup for hot coffees and get a certain amount of discount". (the discounted amount will be decided by Starbucks.

I think this will be very effective as i have put into thoutht that this is how human thinking would be.

*it would be very difficult to make use of new invensions.