Over the past few days, everyone around me seems to have caught on to Zoom, the Silicon Valley–based videoconferencing software company. My elementary school–age kids are using it to keep in touch with their teachers while their school is shut down, and my septuagenarian aunt, under orders to “shelter in place” in the San Francisco Bay Area, reported that her weekly piano lessons will now take place over Zoom as well (as she marveled via text message: “Zoom—who knew?”).

Indeed, the coronavirus pandemic is forcing us to adopt all sorts of new ways of interacting, learning, and working. And for many, that includes using Zoom for the first time. Not surprisingly, the virus outbreak has supercharged demand for the tech company’s video-chat service. Zoom won’t disclose usage numbers beyond its last reported quarter, but CEO Eric Yuan said on March 4 that the company has seen a “large increase in the number of free users, meeting minutes, and new video cases.” Then again, Zoom has actually been zooming for quite some time.

“For years, I told everyone [technology journalists and analysts] they were undercovering Zoom,” says Dan Scheinman, an angel investor who gave Zoom founder Yuan his first check, a $250,000 seed investment, in 2011. “Then it went public, and it was like, ‘Oh, my God, look at Zoom.’”

By going public, he means Zoom’s hot initial public offering in April. Since then, the company’s shares have soared about 200%, giving it a market cap of more than $31 billion.

Scheinman says it was easy for people to dismiss the company when it launched nearly 10 years ago, because videoconferencing was already considered to be a crowded market. To be sure, Microsoft’s Skype, Cisco’s Webex, and Apple’s FaceTime were already in existence in 2011, to name just a few. So why and how did Zoom take off?

I reached out to a few power users to find out.

“Previous to Zoom, I felt like the debate around videoconference apps was ‘Which do you feel is least terrible? Let’s use that one,’” says Hunter Walk, another Silicon Valley–based seed-stage investor. (Walk did not invest in Zoom, but he is a longtime user.) “Zoom had an intersection of stable, high-quality performance plus ease-of-use, and the network effect started snowballing from there.”

Ask other avid users, and they bring up that same theme: While there were plenty of other options out there, Zoom just provided a better one.

“They built a system with a super simple, modern UX [user experience] and very few clicks to get working,” says Aileen Lee, founder of venture capital firm Cowboy Ventures (again, Lee is not an investor but a regular user of Zoom). “You’d think big tech companies with more resources would have been able to offer something as good, but they never did.”

It’s possible that the incumbents didn’t immediately see Zoom as competition. Early on, the fledgling startup went after the education space and small and medium businesses, including young tech companies—classic early adopters who were eager to sign up for a simplified alternative to the bigger, incumbent vendors.

“Zoom has done an unbelievable job making sure they delivered a product experience that was dead simple and worked every single time,” says Aaron Levie, the founder and CEO of enterprise file-sharing service Box.

If you ask Scheinman, Zoom’s first investor, just how the company managed to do that, he says it all comes down to Yuan and his background. The CEO and founder of Zoom spent more than a decade at Webex, but has said repeatedly that when he wanted to completely rethink the collaboration software with a video- and cloud-first architecture, they turned him down. So Yuan left and started Zoom, taking 40 engineers along with him.

“He built Zoom from the ground up, for a world of video,” says Scheinman.

That meant developing a product that was geared to work even with suboptimal Internet coverage, easily available whenever and wherever someone needed to dial in via video. “The architecture was built to work on as crappy an Internet connection as possible,” says Scheinman.

Zoom added plenty of other popular features along the way, from customizable backgrounds to an automated in-meeting transcription service, which theoretically eliminates the need to take notes, helping to set new standards for other videoconferencing services.

“The company was built with the philosophy of making customers happy,” says Scheinman.

“Isn’t every company?” I ask.

“No,” says Scheinman.

I’m betting Cisco and Apple and Microsoft (which owns Skype) would disagree. Earlier this week, Cisco, which owns Webex, said that it too is seeing record usage numbers in light of the virus outbreak. Other companies that offer videoconferencing tools are likely seeing big spikes as well. But video chats are all that Zoom does, and it is now basking in the glory of what it has created—albeit in the midst of a painful economic hit that the vast majority of companies of all kinds will not be benefiting from. Case in point: Over the past three months, Zoom’s stock has risen nearly 63%; the Nasdaq Composite, meanwhile, is down more than 17%. (Cisco stock, in case you’re wondering, went down nearly 26% in the same time period.)

“This is a very critical moment,” Yuan said during a call with analysts that took place earlier this month.

Indeed, the demand for Zoom is higher than ever. As of the end of January, Zoom says it had 81,900 business customers with more than 10 employees. (The company doesn’t break out the exact number of free vs. paying users.) And analysts estimate that it has already brought in more mostly active users over the past two and a half months than in the whole of 2019.

But just how many of its current influx of new users will convert to paying customers remains to be seen. The company offers free access to its videoconferencing software for meetings that max out at 40 minutes; paid subscriptions start at $15 per month for small teams. So far, its chief financial officer, Kelly Steckelberg, has acknowledged that a lot of its recent uptick in usage is on the “free side.”

What’s more, Zoom can expect the ensuing scrutiny, good and bad, to be just as intense as its rapid growth. Already, an optional “attendee attention tracking” feature, which lets video-call facilitators track which participants are focusing on their meeting versus other tabs or applications, is raising some concerns. (Zoom’s online support page says that this function doesn’t track any audio or video.)

Ultimately, though, Zoom has not only managed to quietly turn into the videoconferencing tool du jour. It has managed to do so at just the right time—when, all of a sudden, everybody from my kids and retired aunt to companies forced to join the “work from home” trend desperately seems to need it.

“It turned out that the market for video communication is just so much larger than anyone ever realized,” says Levie, Box’s CEO, pointing to the rise of remote work, billions of mobile devices, and people collaborating globally.

And that was before the pandemic.