I enter the codes just to donate to the national parks. Not really sure who benefits here though as there is no accountability as to whether Coke actually donates what they say they do. Even if they do, the credit goes to Coke for the work that others do in entering the codes, not to mention the tax credits and marketing benefits Coke earns.
Tip for consumers: Use it as a way to donate to some charities if you like the ones listed.