Observation: Delta's weekly email newsletter has sporting event fares, where they spotlight teams which are playing each other and offer the visiting team's fans a chance to go see the game. They catch my attention although I've never flown one before they do appear to be pretty good fares, at least on the routes which I have paid some attention to fares in the past. (Most other airlines' e-fares, including United's, but excepting Alaska's, aren't very interesting to me any more, although I haven't chosen to unsubscribe, either.)