Airlines rely on premium cabins for almost 30 per cent of revenues.
Although just 5.3 per cent of passengers travel in business class or better, they account for 29.6 per cent of revenue, according to figures from the International Air Transport Association.
During this year it is forecast that 4.3 billion passengers will fly on the world's airlines and overall revenues will be more than US$820 billion ($1.1 trillion).
First quarter figures show premium class volumes and revenues in line with that of a year ago.
''Highlighting the importance of the premium cabin to airline financial performance, premium revenues accounted for 29.6 per cent, only a tick below the outcome for last year (29.7 per cent),'' the association said.