China is the biggest country for smartphone sales, representing 30 percent of total sales of smartphones in the second quarter of 2015. Its poor performance negatively affected the performance of the mobile phone market in the second quarter," said Mr. Gupta. "China has reached saturation — its phone market is essentially driven by replacement, with fewer first-time buyers. Beyond the lower-end phone segment, the appeal of premium smartphones will be key for vendors to attract upgrades and to maintain or grow their market share in China."