I signed up to have a filter sent to me every 6 months after letting one go too long and causing major damage to my home. The filter split under the refrigerator, dripped unseen for weeks until the floor joists swelled and began to crack our ceramic tile floor. Having a filter sent to me every 6 months will remind me to change the filter so the new floor won't be destroyed. I wish it would beep when it needed to be changed.