Its a great spacing to be honest with you. As Wes said they are for truss layouts when you feel 2 feet is to far and 16 is a little heavy. Basically over an 8 foot span you can save one truss. It does not sound like much, but on a big home it can add up.
I have used the layout successfully for sleepers on my concrete floor. I laid the sleepers down and then laid hardwood flooring over the sleeps spaced at 19.2 inches. Another great application is strapping layout on basement walls or ceilings. The great thing is, you can get 2 feet insulation stuffed up into the space without difficulty. Its not so cramped though that it compresses the insulation too much.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"