2006.

Bought 25 Kiki tiles with my 250k.
Sold them in exchange as "Kiki Kitty Plushies"
12 Kikis for half off. Everyone went for full trades.

I made nearly 1m on that scam.
Bought stupid crap I wanted, cause I didnt know about OMG or anything...

Was called out 3 days later, never got banned though.