Unfortunately, as far as I can tell neither of the links that wikipedia links to actually contains the 1999 date and if academia.edu was founded in 2008 then th

Unfortunately, as far as I can tell neither of the links that wikipedia links to actually contains the 1999 date and if academia.edu was founded in 2008 then that was after the rules for transfer of a .edu domain were tightened. So there is some real detail missing from how they got the domain name.