You can not compare other companies to Logitech. Logitech is just amazing and go well past what the law requires. They replaced a 5+ year old keyboard I brought second hand, no receipt, no serial number(sticker had worn off) and asked no questions. All I asked them was if they sell spares as one of the keys had stopped working.In fact generally I find manufacturers don't ask for proof of purchase, logitech replaced my mouse and Shure replaced my earphones without asking for proof. They know the product is under warranty because of the serial number.