I disagree with the argument that some products do not seem to enter the Decline phase of their life cycle. Instead, the actual need does not decline while the product can get replaced with one that is more technologically advanced, more creative, and/or fulfills an additional need that the original product lacked to provide. For the suture example, the need to close a wound or incision after surgery remains however the product to do this has changed. Initially this was done with metal staples, which were replaced with the more biocompatible synthetic sutures, which are now being replaced with biodegradable sutures for internal tissues, which will in future be replaced with some sort of sealant gel. I also disagree that staple products take longer to run through their life cycles. Essential product do offer very little differentiation (sugar is sugar, water is water) but they do compete on a price level. A water brand that is too expensive is expected to enter the Decline phase rather quickly. The evidence of this is that these staple products are still, continually being marketed. Basically, all products can decline.