economy class

Economy class:

Passengers often do wonder why pay more when the same service is provided. agents say higher economy class fare and lower class why the difference, the thought often crosses their mind.

Economy class has various classes and fares difference this is not a change in the service provided but a marketing tool .
Lowest fares are usually on first come first serve basis usually lowest economy are promotional or restricted fares.
Higher booking classes are fares they produce because when reach bulk they provide fare to allocate seats at a higher rate demand on availability.
All the above tools are done making sure the aircraft does fly with any empty seat, this makes any role come into play as explained on a former note of mine it is over booking. http://liswith89.blogspot.com/2009/06/why-3-hours-before.html

One example why a higher economy would be purchased is,

On Singapore airlines if you wish for a mileage accrual fare, higher economy fare would be the only option as mileage is accrual on the higher fare never on the promotional fares produced by the airline.

Agents pleased be advised to inform your passenger on all restrictions of the fare you are issuing on,

Re route able or not,
date changeable or not,
refund able or not,

and let the passenger decide there flexibility.

above mentioned is to give you a rough idea about economy class variations the fare,restrictions and why it is caused.

Thank you