SpaceX is not going to lack for customers for all of the rockets they can launch, for many years. They're not going to have to compete for launches in this $/kilo range because nobody can come close, and that opens up customers who just were locked out of space.
There are numerous fine detail errors in this article. I believe SpaceX has abandoned human rating the Falcon Heavy, deferring to the BFR instead, for one.
The publicity generated by launching the car definitely did get attention. A lot of business will come from this.
The author should be careful about comparing listed minimum prices to typical prices for. The total cost of a launch on a Falcon Heavy will surely be more than the minimum because you still have to pay for your upper stage (where needed to raise to/position in higher orbits). Remember, this is just the lift package and LEO circularization that the SpaceX price covers (plus of course tracking, etc.). The typical Delta price listed is for the whole flight.
I'm not saying this isn't cheaper than Delta IV. It almost certainly is. But you can mess yourself up comparing the entire cost of a Delta flight to just the portions of the flight that SpaceX provides in a Falcon Heavy mission.
Other thing, has anyone established what the commercial market is for lifting 64t to orbit yet? Other than military spy satellites, who wants to lift something that big?
The thing to think about here is that Musk's Mars mission needs money. Lots of money. And having left over rockets you can launch for essentially the cost of fuel and manpower is an opportunity to build a money engine that keeps on giving for many years. Just launching stuff into space for other people pales in comparison, where for other launchers it's the only prospect for profit.
The level of thinking here is insane. There are several layers of plot and all of them lead to huge profits to pay for an even grander scheme.
It would be nice to see a table of cost, price per kg, and max payload to LEO, GEO for Falcon Heavy full reuse, center core expended, and fully expended compared to other launchers with accurate numbers.
Which is the point.
All previous rockets were also built by private industry, but nobody cared about low-cost, since the government paid.