Interesting tidbit, courtesy of Randy Petersen, the editor of Inside Flyer magazine:

Among the programs here in America, members have cashed in a total of nearly 193.6 million free awards over the past 25 years (this does not include awards used for upgrades or awards for other than free flight).
Among the programs outside of America, members have cashed in 82.8 million free awards.
Total globally over 25 years: an astounding 276,400,000 free tickets given away (not counting upgrade awards).