Southwest Airlines has an online check-in process that is mildly annoying. For airlines who have assigned seating, one can simply show up to the airport on the day of the flight and check-in at the airport itself. However, Southwest creates a disincentive to do this by having a first-come first-served basis for seating that is based on the order of when the fliers checked in. So for anyone who has flown, this comes down to the almost comical task of setting an alarm for yourself to go off approximately 24 hours before flight so that you can be one of the first ones to check in.
One way that Southwest could improve this flow is to give you an opportunity to automatically be one of the first ones to check-in without having to constantly come back and manually try to check-in. The interesting thing is that Southwest already offers this service! It is called EarlyBird check-in. However, you can only get it at the time you purchase your tickets.
So all Southwest.com has to do is to change their online check-in flow to serve the user the option to purchase EarlyBird check-in in the event that they have attempted to check in too early. Even if a small percentage of users make this purchase, this is still a new untapped revenue opportunity for Southwest.