Alrighty, when people speak of miles loosing their value or being devalued, I am confused.
At what rate are they loosing their value? 1% a year, 10% a year?
So a mile in 2000 is worth what now in 2011? 1 mile in 2000 = .75 mile in 2011?

I understand when airlines increase mileage redemption's like what DL is trying to do, can cause miles to lose value, 25,000 miles to 32,500, -30% in miles value. But that doesn't seem to be the norm or an annual occurrence.

And approx 99.99% of FT members know miles don't earn interest ,so that doesn't need to be repeated, ever!

I am a hoarder, I don't travel for business, so miles comes a little bit more expensive for me. But given there is some devaluation of miles over time, is it really worth it to earn and burn because you believe the miles could loose some de-minimus value in a year's time realistically.
I just want an understanding of this concept? I am not saying its wrong, I am just want to understand that mentality and maybe I am just plain being ignorant.

PS
I just hope its not the same concept a banker will tell me, if you deposit your money into a saving account you could be earning interest, and not in the checking account where it earns no interest. Really banker, really, a whole freaking 1.5% annualized of my $100 monthly deposit is going to affect my finance or life how? But where I have earned 100,000 miles on the non-interest checking account, now that can effect my life. I can save that for a rainy day or emergency, but $18 in interest a year, 5th of Jack on a rainy day.
I guess I should have put down the bottle of Jack awhile back.