In a time of bailouts, it's nice to see a company paying for its own mistakes.
Seriously, this has to be the dumbest thing I have ever read.
How do you figure it's going to cost Blizzard $4.3 million in lost revenue?
No one pays day to day.
The probable way the free day will be applied to accounts, is adding it to the last day of an active account that has not been renewed. I highly doubt the majority of people who decide to not renew their accounts, and stop playing WoW, play it up to the very last day of the very last minute.
"It's my last day of my account being active. Oh wait! What's this! I have an extra day of playing? Sweet! Now I can do some Rep Dailies, put up those Lichbloom on the AH, farm Honor in Wintergrasp. Run a heroic to get that epic..........."