Smartphone sales fell for the first time ever in Q4 2017

"Global sales of smartphones to end users totaled nearly 408 million units in the fourth quarter of 2017, a 5.6 percent decline over the fourth quarter of 2016, according to Gartner, Inc. This is the first year-on-year decline since Gartner started tracking the global smartphone market in 2004.
"Two main factors led to the fall in the fourth quarter of 2017," said Anshul Gupta, research director at Gartner. "First, upgrades from feature phones to smartphones have slowed down due to a lack of quality "ultra-low-cost" smartphones and users preferring to buy quality feature phones. Second, replacement smartphone users are choosing quality models and keeping them longer, lengthening the replacement cycle of smartphones. Moreover, while demand for high quality, 4G connectivity and better camera features remained strong, high expectations and few incremental benefits during replacement weakened smartphone sales.""

Source:  Gartner, 22nd February 2018