On October 13th, the article on Passive Experience which was originally posted on July 12th of 2013 showed there was an update . I didn't post about this because nothing in the article was different. If you compare the 'updated' version with the original word for word, nothing is different . This has been posted a few times on our fan page so I'm addressing this now. Although the rules for passive experience haven't changed since 2013, fighting has. Main and kami accounts also change so there are a number of variables which could affect ones ability to level from passive experience. If you want to ask the experts about passive experience go here.
Original Post (from the Mafia Wars Blog): July 12, 2013
'Updated' Player Support Post: October 13, 2015