From Massively
"The Final Fantasy XI anti-RMT task force has always been very aggressive in their pursuit of gil farmers and gil sellers in the world of Vana'diel, but the latest task force update shows that they're about to get even more technological in their investigations.
Enter the RMT PWNER program, version 1.337. (No, we totally did not make that up.) This program can parse the many servers of FFXI for information regarding the buying and selling transactions of a character under suspicion of the task force. The program will then list all characters who have associated with that character's associates, and so on and so on. This way, the task force will be able to easily track all members of a supposed RMT group without doing all of the human legwork of tracking through endless log files.
In addition, the team is implementing "The Guilded Tomb," a tool that performs quick lockdown of a character's account if the suspicious character carries too much gil at one time, and the magical "Auto-Jailer," a program that will run in the background of all servers and throw suspicious players into Vana'diel's jail once they have met a certain criteria."
If you figure that FFXI has 500,000 subscribers, and that in 2008 "a total of 30.8billion gil was frozen and a total of 88870 accounts were banned" it seem as if nearly 20% of the subscriber base are gold farmers. However, the 500,000 figure doesn't take into account that there is obviously a turnover ratio (gold farmers buying new accounts, new players joining the game vs. old players leaving the game; sort of like societies birth/death rate which would make EverQuest I Europe without the immigration).
At first it may seem strange for a company to essentially cut it's revenue by 20%. There is the argument that not stopping the gold farmers would cause more than 20% of paying subscribers to quit (and with less subscribers, the gold farmers will disappear as well to create a sort of death spiral). However, the greater argument is that every time you ban a gold farmer not only does an angel get it's wings, but that same gold farmer buys another account. The 30% of the FFXI population that engages in RMT then pays more for gold as the farmer raises the price to take into account the banned account and the time it takes to level up another character. We've written about in the past the clear correlation between massive bannings and rising gold prices.
However, FFXI profits from this because it just sold another account which essentially it's paying subscribers are indirectly paying for. It's more or less an indirect tax on the games RMT through "new accounts activation and subscription fees". The more you ban, the higher the tax. Ban too much however and like the Laffer curve shows your "tax" revenue will actually decrease. Either way it's a win-win-win for FFXI (Square-Enix).