Another aspect of advanced fares.

If you buy a RTW ticket, you will want to have premilinary bookings on
each route in order to validate that your itinerary is valid under RTW
rules. While some of the later segments can be OPEN-DATED, they prefer
if you can book everything. For this to happen, flights as far ahead as
possible must have seats available in standard booking classes.


Note however that the above doesn't actually require the airline publish
fares for every booking class that is available. Bit it does require
the airline allocate seats in the booking classes that are valid for the
RTW fare.


There are enough examples where booking a year early is desirable or
necessary. There are examples where this is truly the only way to get
the cheapest fares on a route during a busy season where capacity is limited.

Say you have a 400 seat aircraft. And experience tells you that about
300 are desperate enough to pay full fare in order to travel just before
christmas. That still leaves 100 seats. So they offer apex V class fares
a year ahead, and people first flow to those, which sell out quickly.
You get 100 people who get cheaper fares with the caveat that they paid
a year early for that privilege. And later on, you'll get 300 people who
will pay the full fares. End result: full aircraft.