Weekly commuters like me who buy our tickets weeks ahead of time are not the most profitable customers.
But it is nice, though- I'm booked every Monday 'till July on $50 outbounds (I take someone else home, depending on price, as the last WN flight back leaves too early). Since there's free bags and no change penalty it's a no-brainer. Now, if they'd only have a flight after 20:00 SFO-SNA ...