For a long time, it wasn't entirely clear if Tesla would ever actually turn a profit. It wasn't even always clear if that was the goal. The company burned through cash as it ramped up production, which isn't uncommon--especially among startups.

Of course, Tesla is a little over 18 years old and is the most valuable carmaker on the planet. It's hard to call it a startup at this point. 

Plus, much of its cash problems had to do with a series of manufacturing problems. Musk even famously said that the Model 3, which brought electric vehicles (EVs) to the mainstream with its sub-$40,000 price tag, almost bankrupted the company. 

When it finally did post a profit in recent years, it was largely due to regulatory credits as opposed to, you know, selling cars. That's fine, but eventually, you have to show that you can actually make money selling your product.

Eventually, all of those companies buying those credits are going to figure out how to put together parts and make an EV of their own, even if by sheer luck. When that happens, they won't need those credits anymore, cutting off Tesla's source of profits.

Now, however, Tesla has posted $1.1 billion in profit, the majority of which came from selling electric vehicles. During the most recent quarter, it sold 201,500 of them, mostly the less expensive Model 3 and Model Y, which collectively sell more than all non-Tesla electric vehicles combined. In fact, only $354 million came from regulatory credits, the lowest amount in the last four quarters

That's actually a big deal. More than any other company, Tesla has set out to completely revolutionize an industry that's been around for more than 100 years. That's a pretty big lift. You expect that you're going to have to invest heavily to catch up. You probably expect that you won't make money for a while. 

You can argue all you want that Tesla's mission is about things other than making money, but Tesla is a business. That isn't to say it doesn't also exist for a cause, but ultimately that cause is meaningless if Tesla continues losing money. 

Just because it says its mission is to help convert the world to renewable energy sources, it still has to make money both because it has an obligation to its shareholders, but also because making cars is expensive. Contrary to popular belief, Elon Musk doesn't have a bottomless bucket of cash (or Bitcoin) sitting around to continue plowing into the cause. No business can sustain itself long enough to realize its mission without generating a profit.

But the trend line is moving in the right direction. In fact, Tesla's earnings this quarter were 10 times what they were a year ago. 

If nothing else, the numbers show that building EVs is a legitimate business that doesn't have to depend on selling "get out of emissions jail credits" to other carmakers. It's not that selling clean-energy credits to other carmakers doesn't generate real money, but at some point, you have to move on to making money doing the thing at the core of your business. The fact that Tesla finally is, is good news for sure.