Loyalty programmes are very popular amongst US travellers, according to research by Phocuswright and Acxiom. Around 80% of US travellers take part in some kind of travel-related loyalty programme, with hotels and airlines seeing the highest levels of loyalty programme use. The study also found differences in uptake between different types of people. For example, business travellers and younger people use loyalty programmes more often than leisure travellers and older people. The US digital travel market is currently worth 189 billion US dollars, with this number set to rise to 220 billion US dollars by 2021.