Internet meme started by Youtube parody artist cs188's video "No one need's foundation repair" which has gotten over 100 thousand veiws in a year. Originally just a sound splice of "Job" it has since spread far beyond cs188's videos, as "Everyone's life goal is to get the JOJ". In anti-climax, cs188 revealed "Joj" to mean Jittery Orange Juice.
When writing a baby shower card to a friend, you make a small joke and add, "JOJ". Then your girlfriend walks by and says, "What does 'JOJ' mean?" You then realize that you MEANT to write "JJ" (just joking), but accidentally added an "O". So you say, "Well, it means, just only joking".