currency exchange
I realise how, being an indie developer making a free game, you need money, but I've drafted up a possible idea for free players to be able to make platinum without paying, while you still get the same sort of profit, if not more. Basically, what I'm thinking is a currency exchange. This is implemented in several thousand other online games and always seems to work. Basically, people post offers to sell platinum for gold. Let's say there are no offers. Somebody wants to sell their platinum (which should only be allowed in batches of one to indicate the best deal) for 500g. Another person sees this, decideds to beat that price at 300g and it continues down to, like, 25.
What happens if it stays here? Well, this situation is extremely unlikely, but even if prices are insanely though, you still make money, because when an F2P player buys something for platinum, someone out there is essentially paying for it. Of course, I can see prices more likely inflating to 800-1,000, possibly more, especially if new ways to make money are introduced. Like this, you still make money for all the platinum in the system, you might even make more money with people interested in manipulating the currency exchange, F2P players and left out potentially leading to a wider audience and you never even need to touch the currency exchange as, with a player-run economical system, it adapts itself.
I hope you read this idea and I also thank you for making such an awesome game. :P
Lots of players are doing this with plat item <→ gold trade already, but I might consider allowing plat to be traded directly in future.