Consumer interest in VR appears to be declining, according to sales rank data that we track for Amazon ($AMZN).

We looked at sales rank trends for four major VR headsets from Sony, Samsung, Facebook/Oculus, and HTC. In each case, sales and their respective ranks at Amazon have declined across multiple product categories.

Sony has invested heavily in VR for its PlayStation platform since the 1990s. The PlayStation VR was released in October 2016 for $399. At first it saw decent sales, and its bundle with action-RPG game Skyrim has been most successful for the unit. However, as of late, even that bundle has been seeing dipping sales. In February 2018, it was ranked 29 in its category. Today, it sits at spot 100. 

When the HTC Vive was released in April 2016, experts declared that high-end VR for personal computers had arrived. This $799 VR system built for Windows PCs had the entertainment world stirring, with new games and experiences in heavy development. Today, development for the platform has slowed, as have sales, as the above chart shows. The platform has failed to generate sales or momentum in the VR space for HTC, who is struggling in general after announcing massive layoffs in its Taiwan-based plants just last week.

Not to be left out, Samsung launched its affordable Gear VR headset in 2014 as a way for Samsung smartphone users to get into VR. There have been multiple version of Gear VR, all selling decently, but its even its best-selling unit at Amazon has failed to rank since November 2016.

In March 2014, Facebook acquired Oculus VR for a healthy $2.3 billion. The original Oculus was developed for PCs much like the HTC Vive. Like the Vive, it's expensive and tough to get into for the average consumer, requiring a powerful PC and some computer know-how. The Oculus Go, released in October 2017, promises to simplify VR. It's an all-in-one, wireless VR unit that doesn't require a computer. It also sells for a relatively affordable $249. Initial reviews of the Go were promising, and sales numbers were decent. 

But if sales rank trends tell us anything, interest in the unit is declining. The Go was a top-10 seller in May. Today, it's nearing spot 100.