Not sure why but on a handful of days in early March you can route SAN-SEA and vice versa via DTW if you take the redeye. This will require a full day in whichever city is your destination (which really, who could complain about a full day in either city).

Sample (and one of the only) dates available 03-04MAR. Can probably do it the next Mon/Tue/Wed as well.

I could not get this to show up on delta.com nor on hipmunk. Orbitz seems to work though, I've taken it all the way through to the credit card info page but since I can't use it on these dates not going to purchase.

Hope someone can take advantage. Works out to 2.4 cpm