This isn't necessarily- if you have to think about using that link as charity while shopping, it could decrease your likelihood of doing other charitable things (which is why you should set up a redirect so you don't have to think about it, and you always use it every time!)
Amazon already does that for you -- if you go to buy something without using that link, it'll ask you if you want to.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.