Traveling PDX-KOA, I checked in online and paid for one checked bag. When I dropped off my bag at the airport, the agent said that there was no charge for Delta elites traveling out of PDX, but there would be a charge on the way back. She issued me a refund (which I can expect in four to six weeks). She said she didn't know why, but different stations were doing different things. I hadn't heard of free checked bags at all on Alaska (except when upgraded to first), and the online system obviously didn't recognize it. Something new? Did I get lucky? Was it my smile?