Originally Posted by
cityflyer369
AFAIK you can upgrade from Economy to Business. IIRC we even had a thread here recently where someone posted an upgrade table by AF that showed which fare classes are eligible for upgrade and this table included the option to upgrade from Economy to Business.
This is my 1000th post. :-)
Congratulations!!!

^ -- Your 1000th post is correct too - it is possible to upgrade from Y to C/J although of course only from full fare which often costs more than a discounted business class ticket in the first place!