Just to humor my curiosity: According to the Wikipedia article, the NES sold 62 million units worldwide in total.
Comparing them with the full lifecycle of the NES sales instead of its first 5 years is not a proper comparison.
Lots of enthusiasts did buy the Oculus DK1 and DK2 Rifts, but CV1 was the first time it was actually available in stores and marketed as being ready for consumer use.