United Airlines, along with many other carriers, has instituted a policy of charging for checked luggage. For United, the first bag is $15 and subsequent bags are $25 each. If you check-in for your flight online between now and January 31st, however, you can save $3
on each the first bag. The online check-in process asks for your credit card to complete the transaction. You can also print your boarding pass during the check-in process. When you get to the airport, use the self-service kiosks to start your check-in process again. The baggage tag will then automatically print behind the counter and you'll soon be on your way.
This might be old news for some -- it has been two years since I've been on a flight when I had to check a bag -- but a combined 8-day trip of the OLE project in Lehigh University and the Midwinter meeting in Denver means I'll be out longer than the typical carry-on bag will allow. Still scheme for charging for bags based on a day's flight activity seems a bit foreign to me. The $15-per-day's-itinerary doesn't correlate to any actual charges I can think of. If the main cost of handling checked bags was for the additional labor of handling them, I would expect charges for each segment of a day's itinerary. Likewise, if the charge is to handle the additional cost of fuel to transport the checked bag, it would make sense for the charge to be by segment. So as near as I can figure out, with 15 minutes of thinking about the topic, the added baggage charge doesn't really reflect the cost of actually transporting the bag and is just a way to collect more money.