Alaska Airlines is offering a $50 discount certificate for new Mileage Plan members resident in California who sign up by October 26th, 2012. The discount code is valid for travel between September 5th and November 10th for travel from California.
While prices out of Newark on Alaska are generally not competitive with United for me, Alaska routinely has $168 one-way all-inclusive fares to and from Hawaii out of San Diego, Oakland, San Jose, and Sacramento.