Volume of Gems Undergrad Project
You won’t get this information.
Well you could read up the annual reports of Nexon. Their primary source of income is microtransactions from F2P games. I believe they post their sell through rate, that is the percentage of active players that buy something. IIRC it was just north of 10%.
Nexon had more than $1 billion USD of income last year. They are listed on the Tokyo Stock Exchange.
RIP City of Heroes
I once asked John Smith if he could provide us with similar info (on how much gems were purchased with cash in a month, and what were the numbers on how much gold→gems and vice versa within that same period), but he said that it was too sensitive for release to the public. (Which I completely understand. There are a lot of shady parties who could use that data to the detriment of the player base.)
There’s nothing sensitive about those numbers. Anet just has a policy to not disclose financial information to anyone but investors and I’m sure even those numbers are cloaked in mystery. That said, since the amount of gems/real currency is static, releasing the volume of gems available in the game world could have consequences in-game.
A nondescript graph however could be released and nothing would be disclosed but you could clearly see indeterminate information