If you switch to smile.amazon.com your purchases generate 0.5% for the charity of your choice. As an extra benefit you have an idea just how much you spent with the largest trader in the world. Just multiply your donation amount by 200. The donation amount is easily accessible from the top left of the main page.
I knew my numbers would be high, just how high was shocking.
Then I calculated how much AMZN stock I would have needed to buy when I signed up so that I could have paid for all of it today. That number was ridiculous small.