THE smartphone MARKET used to grow as one of the second hand car, unlike that of phones that are new, struggling in the hold of the great news. According to the analysis company Idc, in 2019, the deliveries of smartphones used are increased by 17.6% compared to the previous year, for a total of 206,7 million pieces (175,8 million in 2018). And the forecasts are rosy for the coming years: in 2023, the number may be equal to 332,9 million, and the turnover in the order of $ 67 billion.