The nascent virtual reality industry, recently reignited by Facebook-owned Oculus VR, was originally focused on PCs: Powerful, upgradeable consumer machines that, paired with the right headset, could create a powerful sense of immersion in a virtual world, at a not totally outrageous price.

But it’s not clear when PC-based VR sets will be widely available. Oculus and Sony have both announced headsets based around the PC and the PlayStation 4, respectively, but neither has committed to a consumer release date or a price.

That means, for most people, their first virtual reality experience likely won’t happen on a PC. In their place, smartphones are being heralded as the entryway to consumer VR. No fewer than 12 headsets based around mobile phones are already available to buy or preorder, with more still to come.

Why mobile? A big reason is convenience: Lots of people already have smartphones, many of which already have the right sensors to offer a “good enough” VR experience, without wires to tie users down to one physical place — think watching a movie that feels like it’s happening all around you while you’re stuck on a plane.

Another reason: The near ubiquity of smartphones potentially makes it easier for consumers to buy into what is still largely a little-known genre of entertainment.

And one more: While users who peer into a smartphone-based VR headset won’t be able to walk around in a virtual world, they will be able to try something and then pass the headset to a friend nearby. I saw this in action at Re/code’s headquarters last week, as we passed Jaunt’s Paul McCartney concert video around the office.

That sort of real-world virality is good, because VR developers need lots of users to figure out what works.

“It’s going to take a lot of people experimenting with this technology to really figure it out,” Dodocase co-founder Patrick Buckley said. “The more people that have it, are playing with it, the faster we’re all going to learn how to really use it.”

Dodocase sells a $25 kit for assembling a simple VR headset, based on Google Cardboard. Users open VR-ready content on their smartphone, put that phone into a slot in the front and hold the Dodocase up to their eyes.

“It’s a basic VR experience, but it’s enough to give people a taste of what it’s like,” Buckley said, comparing VR today to the Internet in 1991. In the past four months, Dodocase has sold 75,000 cardboard kits.

At the high end of mobile virtual reality is the Gear VR, a $200-250 device developed by Samsung and Oculus and set to go on sale in the U.S. next month. It currently works with one phone, Samsung’s Galaxy Note 4, which costs $300 with a contract or at least $800 unlocked — something other mobile headset makers have criticized.

However, Oculus mobile VP Max Cohen praised the Samsung partnership because it allows the two companies to tightly control the experience and plan out exactly how the phone will handle VR content. The higher price is not to increase margins, he said, but rather to guarantee better hardware and technology that will keep people more comfortable and less likely to feel ill.

Cohen said he doesn’t think the mobile VR market is really competitive, at least for now.

“The market is so early that right now, any sort of VR enthusiasm is a great thing,” he said. “It’s not just that the market’s small, it’s that it’s unknown.”

In between the two extremes are headsets like the VR One, made by optics manufacturer Carl Zeiss AG in partnership with German app engineering firm Innoactive. The $100 VR One works with a handful of premium smartphones and comes with a choice of holder for the iPhone 6 or the Samsung Galaxy S5.

Zeiss senior product manager Franz Troppenhagen said the headset comes with a few Innoactive-made apps and a “media launcher” that will aggregate VR content from the two main app stores. The company has collected 150 VR apps on Android so far, and 30 on iOS.

Getting that number up is the shared priority for all the VR guys, although they’re tackling it in different ways. Dodocase is running a Kickstarter campaign to make VR development software for the Web, in a bid to keep content out of closed app stores; Zeiss is planning a developer contest to coincide with the VR One rollout, with the winners being promoted in its app aggregator; and Oculus has released a mobile SDK and is leveraging its developer relationships to get exclusive content in the Gear VR’s app store.

Cohen said his “personal success metric” for the launch of the Gear VR is not unit sales, but rather what developers make for it. The best content, he said, will be made for VR and “something nobody’s made before.”

One hypothetical app he’d like to see? A virtual movie theater that lets people in different locations watch a movie at the same time and hear each others’ reactions. One user could even record him or herself while watching a film and then let another play back that recording while watching the same film later — an “asynchronous social experience.”

“And if they’re annoying you, you could mute them or move them away to another part of the theater,” he said.