CompAndSave does not accept empty cartridges for a credit. You can visit your local office-supply stores like Staples and Office Depot as they give credit in exchange for a qualifying empty cartridges that you turn in. Please bear in mind that these stores will only accept the original or OEM ones.
For recycling of compatible ink and toner cartridges in the USA, here are a few sites that we would recommend:
US Recycling buy back empty compatible and remanufactured cartridges.
Milner recycles both ink and toner cartridges whether they are OEM, compatible or remanufactured.