At the end of 2007, the top 10 US MNOs served a total of about 250m subscribers, but with operator' subscriber base ranging from less than 1m to over 70m. This gives an idea of the relatively strong concentration in the US mobile marketplace. The top 4 MNOs accounted for 218m subscribers or about 87% of the US market. ATT Mobility and Verizon Wireless are clear leaders, battling for the pole position in buying smaller operators (Dobson for ATT and Rural Cellular for VZ). They respectively had 70.1m and 65.7m subscribers at the end of 2007. At a distance is Sprint Nextel with 53.8m that differentiates from the others with very low net additions in 2007 and a higher churn. But the fourth MNO is T-Mobile at a respectable distance with (only) 28.7m subscribers, and will need time to pass over Sprint Nextel, despite a strong growth rate. It is likely that some further consolidation would take place in the market, but when and how remains the $100 question. The situation is complicated by different technologies used by various MNOs: CDMA for VZ and Spring, GSM for ATT and T-Mobile.