3DS sells over 6 million units in Japan
Regional sales totals are not available for the 3DS's main competitor system, the PlayStation Vita, which was released in Japan about ten months after the 3DS and two months later worldwide. However, the 1.8 million systems sold to date worldwide provide contrast.
The 3DS suffered similarly slow sales in the period before its price drop and holiday releases; as of April of last year, it was at 3.6 million worldwide. That's slow, even if it is twice the Vita's current life-to-date total.