Nintendo sold more than 1.5 million Switch units in Japan during the system’s first six months of availability, despite hardware shortages that found consumers lining up for pre-order lottery events. That success must be especially heartening for those who feared Nintendo might repeat its performance with the Wii U, which sold well during its first few weeks but didn’t maintain that early momentum.

The data comes from a Kotaku report, which is based on information gleaned from a hardware sales chart posted on 2ch.net.

During its first week on store shelves, Switch sold 329,152 units in Japan, compared to the still impressive 309,154 PlayStation 4 units sold during that other system’s launch week. Nintendo sold 61,998 units the second week, slightly below the 65,685 units of Sony’s hardware that consumers purchased. After that, however, Switch didn’t have a week where it failed to outperform the PlayStation 4.

Keep in mind that the Switch and the PlayStation 4 launched under very different conditions. Nintendo’s home console and portable hybrid reached stores in March, which is typically a slower season for hardware sales. The PlayStation 4 arrived in early November of 2013, which put it in prime position to enjoy early sales as holiday shoppers decided what to put under their Christmas trees (though that also meant increased competition from other gadgets and even software for then-current platforms).

Strong performance in Japan might not seem critical at a glance, since North America is a more lucrative market, but remember that the Switch is selling well there too. As developers consider what platforms should receive ports of their current and future games, the strong early performance will certainly be a factor and that could pay huge dividends a year or two from now.