What's the difference between buying air miles versus buying an airline ticket? What is better?

Question

What's the difference between buying air miles versus buying an airline ticket? What is better?

Answer 1

I'm not sure I understand your question.  

I have found over the years that if you are a frequent flyer, you use the miles for upgrades, not for free flights.  

So to me it's worth it to get enough miles for an upgrade; I would buy them in addition to getting a ticket.  (Of course, you have to get a full-fare ticket to qualify for the upgrade.)

Answer 2

Air miles are credits that you can redeem in many variations and one of them are airplane ticket for the company you are flying with.

You can redeem the air miles when you have over 10,000 for example.