Hey all - don from D'Addario here. Today we announced the world's first Guitar String Recycling program.
The recycling program is called "Playback" and it rewards you for recycling ANY brand of used strings, not just ours. Shipping the strings back to us is prepaid - all you have to do is print out the label - slap it on a box. Please note that this is a very new initiative and currently only available in the US.
You can learn more about it here - Playback - The World's First String Recycling Program