With its flimsy cardboard viewers, no one could ever mistake Google Cardboard's virtual reality experience for the high-octane Oculus Rift or the soon-to-be-released Sony Playstation VR headset.

And that's the point. Google Cardboard aimed to get as many people using virtual reality as possible during the early stages of the budding technology. All users need is to slip their smartphone into the viewer.

That appears to have paid off. Google Cardboard, a subsidiary of the newly formed Alphabet Inc., said Wednesday it had shipped five million of its foldable cardboard viewers since they were first offered 19 months ago.

In that time, 25 million Google Cardboard apps have been downloaded from Google Play and users have watched more than 350,000 hours of VR video on the devices, the company said.

The sheer numbers give Google something of an edge as the VR wars begin to heat up. That can quickly change, of course, if consumers decide they prefer the computing power of a Playstation or even the more immersive headset offered by Samsung, which also requires the use of a smartphone.

It will cost you, though. Google Cardboard is priced at around $20 (the company even offers instructions on how to make one yourself from scratch). A Samsung Gear VR headset costs about $100 and the Playstation VR is expected to cost hundreds of dollars.

A recent survey by Frank N. Magid Associates showed that video gamers identified more with high-end VR devices than the more casual Google Cardboard.

When polled, one-quarter said they were aware of the Oculus Rift, followed by Samsung VR Gear at 21%, PlayStation VR at 20% and Google Cardboard at 17%.