The big dog in FF programs, and the X factor in valuing miles, is the (apparently) legal right of the airlines to change awards at their will. You can't measure what you have saved with a mile until you've actually used it to save money you would've otherwise spent.

That's why to me the threads that suggest people incur costs of, say 2 cents a mile to earn miles because one can look over at an award chart and compute theoretical savings of 2.2 cents are nuts.

United just raised the cost of the award I use most (upgrade to Europe) from 40,000 miles per trip to 60,000. And buried in the data are the fare increases over the past 3-4 years which mean I can no longer upgrade a $700 coach fare but must now pay $1,100 to do so.

**** right those miles are worth less. And they may be worth even less tomorrow.