What is Zenny Exploit?
1.
a glitch in a game that results in gaining money basically for free.
taken from ragnarok online.
alternately; anything that corresponds in real life, like confusing clerks at the grocery store to enter discounts on items that are far too high.
'So wait, if this powerade is 5 for 5$... and its buy 2 get one free... i can get 7 for like 4$.'
"dude, thats one hell of a zenny exploit."