Even the hottest, fastest-growing companies cool into a slower growth maturity. Apple has experienced years of blistering sales of its iPhones, which sold out in hours after their introduction. But now, it suddenly seems its latest line of phones might not be selling as well. Availability of the XR model has remained steady, and there doesn’t appear to be a run on it. If that is the case, it might be a rare miss for Apple or at last, the public is exhausted and not as eager to buy. Apple has depended on phone sales for superior margins over the last decade. Should its popularity be over, it is a serious concern for the company. There are things marketing and PR can do to reignite interest when it wanes. One hopes those plans and tactics are ready to implement. Apple has an enormous cash cushion on which it can run for years, but financial analysts will discount that if iPhone sales are down and they will hammer the stock.