In the past, miles granted to a flyer in an airline loyalty program were based on miles flown.
However, that has since changed so that miles granted are related to purchase price of the ticket, not simply actual miles flown.
Regardless of whether units in a loyalty program are called miles, points, or some brand specific name, for the rest of this page I will refer to units in a loyalty program generically as points.
An airline or hotel chain may have a loyalty program that awards members points that can go towards future travel.
The loyalty program may or may not have tiers, where each higher tier provides greater benefits.
A consumer can advance through the tiers by meeting the requirements of each tier.
Points in a loyalty program can be "earned" in the following ways:
In addition to the ways listed above, you may also be able to purchase points.
The normal cash rate charged for points in a loyalty program is generally a poor value.
A travel loyalty program may or may not periodically have special offers that allow you to buy points at a reduced rate.
However, even with such offers, buying points is generally still a poor value.
The edge case where buying points, even at full price, can make sense is when you need a small number of points in addition to what you already have in order to have enough points for a specific redemption.
Just as with cash, the spending power of points may decline over time.