Jim, this hasn't happened before.
VR isn't 3D, it didn't come and then just go away before, it was demo-ed at events and arcades in the past. The tech to make it available to people simply didn't exist. This will be the first time it's come, no one actually knows what's going to happen. Granted, I don't think it's going to sell like cel-phone games, and I don't think it's meant to. Like a beastly graphics card or gaming rig, it's a "only serious gamers need apply" type deal, and while I can't speak for Facebook, hopefully the Oculus team has realistic expectations on this.