VR desperately needs a killer app, that experience only it can provide and that everyone wants to use. Killer apps are fundamental to a gadget's success: the original Xbox had Halo, the iPhone had the app store, Black-Berry had BBM, and Blu-ray had, um, porn. Without a killer app, a gadget is destined either for the wilderness of niche usage (3D printing) or the graveyard of forgotten tech (3D televisions). And VR desperately needs a killer app.

When I say 'desperately', I refer to Facebook. Since buying Oculus in 2014, Facebook has put 10 000 of its staff to work on VR. It's spending enormous amounts on the technology, serving a market that will only ship seven million units this year, according to new IDC figures. That's a million units for every year Facebook has owned Oculus. To compare, Fitbit shipped seven million units in 2021. So even one vendor in the lukewarm fitness wearables market outpaces the entire VR market.