Amadeus claims over two-thirds of global air bookings are now eligible to include an ancillary service.
The 70% figure comes from data released by the travel tech giant to illustrate the growth of such services during 2017.
These ancillary services are now also available via third parties, such as travel agencies (on and offline), marking a significant uptick in the amount of ancillary products going through in-direct channels.
According IdeaWorks, airline ancillary revenue was projected to be worth around $82.2 billion on a global basis in 2017.
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The company says some 115 carriers on its books had implemented ancillary services by the end of 2017 - up from 94 at the beginning of the year.
Fifty airlines - an increase of over a third from January 2017 - are also using Fare Family-type products as part of their ancillary revenue strategy.
Overall, Amadeus says it saw over a 30% increase in the volume of ancillary services sold via intermediaries during 2017.
This is on the back of a 25% jump in the number of travel agencies now selling ancillaries, it claims.