Update 9-19-2014 : I booked a flight to Hong Kong this week on Delta and did not need to wait until the next day to access Preferred seating. Once I completed booking (with my Alaska Mileage Plan number added) I was able to immediately head over to Manage My Reservation and select Preferred Seating.
As I’ve mentioned in my previous post, I’m not a big fan of calling up Delta Airlines unless I must. I’m an Alaska Airlines MVP which gives me access to varied reciprocal benefits on Delta. While these benefits have reduced over time thanks to the strained friendship between Delta and Alaska, the perks are still better than no status at all.
While I automatically have access to Preferred seating on partner flights when booking through AlaskaAir.com, when booking on Delta.com, their site does not immediately recognize my MVP status during booking. On the seat selection page, you will find that standard and Economy Comfort seats are the only available option in Economy. Therefore, unless I pay for Economy Comfort or a paid upgrade to Business, I’m relegated to the standard, back-of-the-plane or middle seats. However, the trick is to return to your Delta reservation on Delta.com 24 hours later and you will suddenly find that the dark blue Preferred seats are now at your disposal at no cost.
Now, I’m standard MVP, not Gold or 75K MVP, so if you have higher status, your experience may be different.I was able to snag the aisle seat in an exit row for no additional cost. I booked a flight from TPA to DFW last week and 24 hours after my original booking, I was able to snag the aisle seat in an exit row for no additional cost.
Calling into Delta is an alternate, immediate option after booking to request Preferred seats. But if you’re in no rush and your flight is only half full like mine was, calling into Delta wasn’t worth the trouble.

I was able to snag the aisle seat in an exit row for no additional cost.