The cash sale for real moneys. As I recall when I started gree was selling in game cash for about 10000$ for 99.99$. This scam fools new players into spending cash for something of little value ingame, and especially as different level players can buy a higher amount of cash for the same price. Not to mention events like the buckshot rewards the same amount if not more for completing a single beginners quest. In some cases you can earn more for robbing the right hoods and attacking the right players.