[Note from Affairs of M/Men: I don't buy books from Amazon if I can help it (some ebooks are only available there), but I spend a lot of money buying from individual companies through their marketplace.]
As an FYI, if you have an Amazon account, Amazon just released a new program called Amazon Smile that costs NOTHING to you. You can pick OPS (Oceanic Preservation Society) or just about any other charity/organization of your choice and Amazon will donate .5% of your purchase cost to the charity every time you buy an eligible product.
I already buy most of my things from Amazon, so yay! Glad to know a small portion of the cost will be going to an organization that I really love.
EDIT: Details of the program can be found by clicking here. This MAY work for all Amazon members, but it's not very clear.
EDIT 2: It seems to work for ALL members, not just those with Amazon Prime.