This is one of the reasons Costco has been so successful, their satisfaction guarantee has no time limit on returns outside of the 90 day policy for electronics.
I personally buy things there more often due to them backing their products so much that even years later I can return it if I'm not satisfied. As a former salesman of products within Costco, I would see our products returned from sometimes a DECADE prior. As a salesman I hated it, but even though people abuse the policy it's a good thing overall IMO.