What would happen if Apple's iPhone X flops?

iPhones are a big deal to Apple. The product line in any given quarter, according to Motley Fool columnist Evan Niu, represents 60 to 70 percent of the company's revenue. That's why Apple makes a big show out of its iPhone launches and, until now, all have been successful. The new iPhone X introduction was met with rave reviews, and yet some are seeing the possibility that Apple might face its first iPhone flop as a result of its inability to meet consumer demand for the product. "In no uncertain terms, a failed iPhone launch is investors' worst nightmare," writes Mr. Niu.