Nintendo's new NES Classic Edition consoles are proving so popular that getting hold of one has been an impossible task for many fans. The machines sold out quickly once they arrived in the stores - both virtual and physical - resulting in some appearing on eBay for two or three times the $60 retail price. Unsurprisingly, it turns out that a massive 196,000 units have been sold in the US since they were released in November.

The figure comes from game industry sales tracking firm NPD group (via GamesBeat). It's almost as high as the number of Wii U consoles that were sold in the US during the six-month period between April and September - 220,000.

The NES Classic Edition sales could have been much higher, if only Nintendo had anticipated the demand and made more. The company is trying to get extra units into the hands of retailers in time for Christmas, but many of the new machines are being used to fulfill orders placed in November.

Nintendo assures people that it is not deliberately holding back units. "Every day there's more going into the retail channel," Reggie Fils-Aime, president and chief operating officer of Nintendo of America, told CNET. "The overall level of demand is certainly greater than we anticipated, that's why we're suffering through the shortages out there in the marketplace."

Google's annual "Year in Search" list for 2016 showed that the NES Classic Edition was the seventh most popular consumer tech search term in the US. It was also the most second-most Googled games console of the year, sitting behind Nintendo's other device, the Switch.

For those still looking for a Classic Edition, GameStop reportedly took in "limited quantities" of stock yesterday, with more set to arrive today.