Adding yourself to the waitlist simply means you are on the waiting list and new people added to the waitlist will theoretically (because no one really knows the details of how the waiting list calculates who gets in and where) get added to the waitlist after you. So, the sooner you do it, the better chance you have of an upgrade according to the rules below.

The rules that apply of who gets the seats are the following:

If U seats exist the following hold true:

1) at any point in time:
- Anyone can upgrade using 10,000 AS miles
- Anyone can upgrade using an Upgrade certificate (ie: MVPG guest certs)

2) at 72hrs before the flight:
- MVP Golds on the waitlist start getting upgraded, in order of waitlist

3) at 48hrs before the flight:
- MVPs on the waitlist start getting upgraded, in order of waitlist

4) at 24hrs before the flight or during checkin:
- anyone can upgrade with cash during check-in time at the airport
- Northwest elite members can upgrade using their certificates
- waitlist is transfered to the airport
- it is usually pretty rare that U seats get this far down


ps: You can somehow guess your chance of getting an upgrade by looking at how many F seats are available, meaning, if there is only 1 F seat available, then it is impossible for more than 1 U seat to become available, unless someone currently holding a seat in F gives up their seat (or if AS was holding a seat back, even from FC purchasers, and decide to release it at some point in time)


hope this helps breaks it down,