Is air courier travel real and possible?

In the world of air travel, are Y-UP fares real?

• I've heard about Y-UP fares.  Essentially, what I have heard is that one can purchase a first or business class plane ticket for the price of an economy ticket.   Is this true?  How does one go about purchasing a Y-UP ticket?

• Answer:

  Yes, they're real. But they're usually based on either full-fare coach or a very expensive coach fare. If you're looking to upgrade on a cheap economy fare then you usually have to be a very frequent flier and those upgrades are usually on a space-available basis. (The YUP fares eat into this availability.) I haven't seen YUP fares on international flights, though discounted business and first is sometimes available. I sometimes see this over Thanksgiving from U.S. to Europe when business travel is low.