...oddly enough, the article talks about this point.

It's not standby, but you have to book within three days of departure. So it's pretty close to the bottom of the barrill.

The fees and taxes should also be eye-opening...

Someone will try to use it for a regular commute, but will find that X % of the time, no seat is available. Ooops! "...But for $400, we can get you there on Monday morning..." They'll get mad. Schedule for Tuesday. Take Delta Monday, thereby no-showing on JB Tuesday. Ding! $100 fee, pass invalid.

Etc.

Sounds potentially like a pretty smart gimick to me. Lots of buzz. More revenue. Good on them for trying something.