October 2017 is the 45th month of the PlayStation 4 being on sale in Japan. The gap grew in favor of the PlayStation 3 by 9,068 units in the last month and in favor of the PlayStation 3 by 58,744 units in the last 12 months. The PlayStation 4 currently leads by just 6,468 units.
The PlayStation 3 launched in November 2006, while the PlayStation 4 launched in February 2014. The PlayStation 4 has sold 5.45 million units, while its predecessor the PlayStation 3 sold 5.44 million units.