One thing that frustrates some players in MMOs is the use of multiple forms of currency in the game. A lot of players just want one simple form of currency to use for everything, just like they do in real life. And the problems associated with real life currencies are just as valid in an MMO as they are in a country’s economy.
Most games (pretty much every one I could think of) have a reward system that creates currency as it is needed. Whether it is gold, influence, ISK, or gil, the game creates it out of nothing when you earn it. As you do what the game asks of you, you are rewarded with more and more of the currency you are seeking. We’re essentially printing money, and many countries have collapsed under such inflationary tactics. Now in order to placate massive inflation, games put in “money sinks” (or simply “sinks”) into their economies so that players do not end up with a near infinite amount of currency.
Sinks are great in theory, but if done perfectly, they will frustrate the player. Why? Because their coffers will never get bigger. Every gold they earn is spent in maintaining whatever sink the game has thrust upon them. From a game balance perspective this is preferred, but it is not fun. Players want to accumulate wealth, as a symbol of status, almost like an XP bar.
One solution to this problem is to add a new form of currency to the game when you add something new for a player to acquire. This evens the playing field when that new thing is introduced. Captain Moneybags can’t just go and buy everything new on day one because you tied it to a currency that he has in abundance. If you did, Captain Moneybags would complain on day two that there was nothing new in the game for him.
Another reason this is good is because players tend to migrate towards the fastest time:reward, or easiest risk:reward ratios your game has to offer. Even if it’s grindy, boring, content, if its fast AND easy, players will flock to it and ignore any other content your game has to offer. This will give them an abundance of currency with not enough to spend it on.
That said, you can’t completely ignore hyper-inflated currencies. You can and should give players some “perks” for purging their cash reserves. Maybe they can’t buy everything in the new store on day one, but they might be able to get stuff at an accelerated rate from the rest of the populace by spending exorbitant amounts of currency for the privilege.
Another trick is to introduce two new currencies at one time. One of these currencies is “farmable”, earnable all day and every day in the game. The other of these is limited to only being able to be earned at a trickle, with cooldowns and lockout timers on earning them (earning them a second time within the cooldown period should earn the player the farmable-type of currency instead.) WoW did this with their Badges currency, and iterated on it with their latest Justice/Valor points system.
I may revisit this subject in the future, so I’ll stop now and read your feedback before delving further.