The product life cycle is a familiar one in marketing. A product is launched, developed, goes through aperiod of growth, enters maturity, declines, and eventually dies. A top brand should go on and on if it is well managed. A brand manager is like a doctor or plastic surgeon, who can keep the brand healthy and looking fresh down the years. Brand managers must be able to identify new segments of the market, particularly when products have become mature. Coca-Cola has introduced a large number of variants to appeal to different consumers. So knowing what stage your branded product is at in this cycle may help you decide when to launch a line extension or for a relaunch with improvements and "added-value" features. Newer versions of car, for instance, will come with air-conditioning as a standard feature, or they will have a facelift to modernize the look even though what's under the bonnet may stay the same.