Join Date: Oct 2005
Programs: Delta, American, USAir, Continental, Northwest, United, AirTran, SouthWest, Midwest
Posts: 563
They do expire after 30 days. So that's the "game" for my wife. She tries to use her ECB's within the 30 day period, but only on things that generate more ECB's for her. So she buys stuff she doesn't need just to extend the expiration on her ECB's (by replacing them with new ECB's).