With all the ventures Elon Musk has, the fact that he also needs money to run them is commonsense. His newest enterprise, a tunneling and infrastructure business, is called the Boring Company, and as of now, the only business it has (that is, a source of actual revenue) is selling hats.

This is no joke. Musk announced in October that the company was starting the sale of the hats, at $20 a piece (including shipping and taxes). And on Sunday, the billionaire entrepreneur announced on Twitter that the sale of the hats was being capped at a total of 50,000 pieces, and also that the company had already sold most of them.

The math behind the numbers is easy, as was pointed out by some of his Twitter followers.

However, as of Nov. 21, only just over 15,000 or so hats had been sold, so maybe there was a sudden spurt in sales in the last 10 days that would explain how the company is “almost” at the 50,000-mark already.

Musk clearly has a sense of humor, but maybe there is some truth to his reply to someone who asked if this was how the company was being funded.

But then, Musk also posted another tweet, with a clip from the 1987 parody film “Spaceballs,” calling it a documentary which taught him about the power of merchandise.

Still, Musk is selling the hats, and in his own way, promoting them too. He even let on that he could be the delivery man (unlikely).

Like everything else with the Boring Company, the prized autograph of the delivery man will be boring too. Musk also gave some other details about this special delivery.

And responding to another Twitter user who questioned his obsession with the hats, Musk had self-deprecating answers ready.

If you want to buy a Boring Company hat, you can order one from this page.

But the company is looking at actual business too. Musk announced Nov. 29 it would bid to build an express service that connects downtown Chicago with the O’Hare International Airport.