Airlines charge progressive luggage fees because they have discovered that flying air freight on passenger flights is highly profitable. Air freight rates generally range from $1.50–$4.50 per kilogram. Airlines typically price airfreight at 4–5 times that of road transport and 12–16 times that of sea transport. 1st Bag: $30 · 2nd Bag: $55 · 3rd Bag: $180 · 4th Bag: $200 · Each bag maximum 50 lb/22 kg. Companies shipping cargo like smartphones that are very valuable when priced by weight (a kg of iphones is worth thousands), don't care if they have to pay 15 times the ocean transport rate, if they can get them to market much faster and securely by air transport. Airlines don't want to lose space in the cargo hold for that business because their passengers want to check 2 bags and their golf clubs on vacation with them. The baggage costs are as much about discouraging checking baggage and incentivizing carry-ons as they are about makeing extra money off the passenger business.