The emergence of low-cost carriers (LCCs) in the early-to-mid 1990s opened air travel to customers who otherwise might not have travelled by air or at all.Full-service airlines responded with changes to their cost structures and either re-positioned themselves as LCCs, or they pursued a hybrid strategy of maintaining frills on the legacy carrier but setting up a low-cost subsidiary airline.In 2010, long-haul (transatlantic) LCCs had emerged, including Norwegian Air Shuttle ASA and WOW Air hf. In 2018, there were 47 aircraft in Europe deployed on long-haul, low-cost routes.Revenue drivers in the industry included capacity, passenger yield, load factor, additional charges and fees, and cargo.However, over time, the low fares of LCCs began to attract the customers of legacy airlines.