What's the scoop on upgrade <BR>coupons? Where does one get <BR>them?

Typically, airlines give upgrade coupons to their more/most frequent flyers. <BR> <BR>As an example, I am 2nd tier elite (Gold) with USAirways. To reach this level, I fly &gt;50K miles per year with US. I receive a total of 18 upgrade coupons for every 20,000 miles that I fly with US in a year. Each coupon can be used for a one class upgrade for a distance of up to 800 miles (not good to Europe). Additionally, US annually sends me one round trip upgrade that is good for travel to Europe or any place else on their system. <BR> <BR>On US, silver elites (25K miles/yr) receive a total of 10 800 certificates for 20,000 miles of travel. US' top flyers (&gt;100K miles/year), receive unlimited upgrades anywhere on US' system; except for Trans-Atlantic travel. <BR> <BR>Upgrade programs vary wildly between various airlines, but I think US' program is one of the most generous. The real key is that you must fly a significant with a particular airline before you start to receive these upgrades. <BR> <BR>Note these upgrades are received at no cost to the flyer and separate from upgrades 'purchased' with miles

Here's the thing... I paid less than $600us for my restricted coach ticket. I am flying to Paris and returning to the US from Rome. Using 40,000 miles I have been upgraded to Business Elite both ways. How? 1)Perseverance(calling every other night, late at night, to check change in upgrade availability). 2)Coach is full. 3)Plain luck, calling the right airline operator at the right time. This time it worked for me. I hope the rest of my trip is as lucky and comfortable.