The Travel is a low profit margin industry that always drives itself and finds creative ways of maximizing profits. Travel Agents work hard and long to ensure that every PNR captured makes the most amount of money possible for themselves or their agencies. Mining the GDS and finding these creative ways to make money constantly mining can be a complex, costly and time consuming process.
When the fare is revalidated before the checkout page by the booking engine. It instantly starts to hunt for a lower class in the background and if it finds as they booking as taking place â€“ it then creates the PNR in the lower class and price difference (not displayed to customer or partially displayed to customer) becomes the markup in the background.