Tesla has always been wary of too much demand for its cars.

But analysts and experts who follow the company have often worried that there isn’t enough demand for Tesla vehicles.

For the past two years, on nearly every quarterly conference call to discuss Tesla’s financial results with analysts, this issue has come to a head.

CEO Elon Musk is asked about demand for the company’s vehicles. And his answer has always been the same: Tesla doesn’t have a demand problem — if anything, Tesla has production issues.

Musk usually explains that Tesla is “production constrained” — not “demand constrained.”

He then often segues to his view that Tesla can stoke demand whenever it wants. It’s a critical element of the way Tesla does business: The company doesn’t want demand to get out of hand.

Why? Because if Tesla can’t supply that demand, customers have to wait to get their cars.

But analysts haven’t always believed Musk. There was intense focus on Tesla demand at the end of 2014 and through all of 2015, as the automaker prepared to roll out its second built-from-scratch vehicle, the Model X SUV. The scrutiny implied that Tesla demand might not be as strong as Musk was suggesting. So did it make sense to launch a new vehicle, the Model 3 mass-market car, if demand for the existing products was sagging?

We now know that Musk was right all along, and that there was abundant demand for Teslas out there in the world. Anyone who doubted the untapped craving for the brand was refuted by the preorders for the just-unveiled Model 3: 400,000 and counting, at $1,000 a pop to reserve a car.

It’s not inconceivable that preorders could top 500,000 — which is Tesla’s production target for all vehicles by 2020.

This all raises an obvious question: Can Tesla actually build that many Model 3s and deliver them on time?

Miles to go

Given that the company’s maximum production so far was a bit more than 50,000 in 2015, and that it’s guiding for less than 100,000 in 2016, it’s clear that Tesla has a long, long way to go to get to 500,000 in a mere four years.

The Model 3 debut unleashed the demand that Musk was always talking about as a key worry for the company. It also made that demand concrete — in the past, it has been vague. If half a million people are willing to donate $1,000 to Tesla for an indefinite period of time, it proves that the Tesla market is sizeable.

Now, you might argue that all of those preorders, which could bring more than $16 billion in revenue into Tesla’s coffers if the company can make good on production, represent all those Tesla wannabe early adopters who couldn’t swing the $100,000 purchase price of a Model S or Model X. Once that group is exhausted, perhaps Tesla will have captured all the customers that currently exist.

Well, maybe. Or perhaps the Tesla market is in fact HUGE. At least, far larger than it had looked up to the Model 3 reveal.

One thing is sure: Musk and his team didn’t ease us into exploding demand. They flipped a switch and let it flow.

This story originally appeared on Business Insider. Copyright 2016