Quick post because I’m awfully busy today. There’s a FlyerTalk thread discussing a PHL-SEA mileage run on UA via Houston for $260.20. You can book this the other direction, too, SEA-PHL. However, if you look a little closer you can find availability as low as the $230 range, bringing it down to roughly 3.7 CPM.
Even weekend trips can be had via SFO and IAH for under $300. If you’re not a UA fan, I found DL trips out of PDX that are also under 4 CPM. So look around. There appear to be some deals today. Even though today’s another gloomy Seattle day, don’t forget that it’s Always Sunny in Philadelphia. 😀