Alcohol (spirits as the industry calls it) processing is a very interesting process which I fortunately learned intimately as I implemented a system for one of the larger bourbon distillers in Kentucky (Was there for about a year). It's also one of the most profitable business models I've seen as they make money at every step on the process.
The process goes something like this. They first distill the grains (mash) and out of it comes neutral grain spirits (basically straight up moonshine). They cut down the potency and then put it into brand new charred oak barrels (they have to be this way to be considered Bourbon). They sell these barrels to the distributors (profit), they then charge the owners of the barrel a yearly fee to store them in the distiller's warehouse (profit), when the distributor decides to bottle the barrel (anywhere from 4 to 20+ years later) they charge them for bottling it (again more profit), etc, etc...
There's one point where the article is not correct from my understanding. The used barrels are typically first sold to Whiskey distillers (i.e. Scotch) and then once they've been used in whiskey is when they're used for rum. You can see and taste the oaky taste difference from a Bourbon to a whiskey to a rum. This is all very interesting stuff to me.
BTW out of the stuff I drink on a somewhat regular basis my favorite Bourbon is Maker's Mark, favorite Whiskey is Vat 69...I know, I know is cheapo stuff, but I've had some of the best ones in the world and still like Vat 69's taste. It's definitely an acquired taste as it's harsh. Favorite Dominican rum (Brugal de mallita). Favorite rum altogether Havana Club and Babancourt 5 star.