Currency Re-selling in Neverwinter

A double exp weekend finally got me to try out Neverwinter a year into its run - I played a few hours in beta, had no particular problem with the game, and just didn't get back to it until now.  I was a bit surprised to find that the business model appears to emphasize currency resale on a scale I would have associated more with an underwhelming Neal Stephenson book.  By making the game's primary currency extremely inconvenient to farm, Cryptic has somehow carved out a niche where it puts non-payers to work farming currency to sell to people in exchange for cash store currency (which they pay Cryptic for in real money).  

The Economies of Neverwinter
Neverwinter's primary currency is tied into the game's business model in a way that isn't possible for games that had to retrofit a payment model revamp post launch.  If you were to take WoW non-subscription today, you'd have years of player experience that gold is the currency for all player and many non-player transactions, and you'd have a massive inventory of gold already in the economy to deal with.  Instead, Neverwinter started with a clean slate.  Some context on the various economies:

• There is gold in the game, looted from mobs and used to pay NPC's for some things (primarily common consumables), but notably is NOT the currency for the auction house.  
• There is a cash store, with a currency called Zen (common name for all Perfect World games, though the actual funds cannot be transferred).  This contains all the usual stuff - bags, mounts, outfits, etc.  There are some places where the game mentions that you can buy stuff with Zen, but it's nowhere near as common as many other titles.   
• There are the obligatory tokens used to barter for gear.  These at least go into a currency tab as far as I can tell. 
• The game includes the ubiquitous obnoxious item gambling lock boxes, which you have to manually destroy out of your inventory because they are the only item in the game that is automatically picked up upon walk-over (like gold).  Like many other titles where these have a bad name, there is zero transparency about drop rates and a server wide spam message claiming that someone has won the top prizes, though I see many less of these than I do in other games. 
• The game does NOT include an optional subscription, charges for content, etc. 

All of which brings us to Astral Diamonds. 

Using and Trading Diamonds
Diamonds are the currency for the auction house, and the majority things that you would expect to pay for in an MMO, including consumable components of crafting, tier upgrades for gear/mounts/companions, along with some free-to-play additions like instantly refreshing cooldowns in most mini-game systems. 

The primary source of diamonds are a variety of daily quests or other objectives.  The currency is routinely looted in quantities of a few hundred or maybe a thousand, is routinely spent in the hundreds of thousands or even millions on the auction house, and can't really be farmed short of planning your entire life around logging in every hour to take advantage of every last event and cooldown that offers diamonds as a reward (which still has a hard cap of 24,000 diamonds per day).  The only quick way to obtain more diamonds is to pay other players. 

In addition to the auction house, where players can trade items (including many cash store items, as long as they aren't account-wide), there is a separate currency exchange used to swap between the Zen - which you can purchase from Perfect World at any time - and Astral Diamonds, which are farmed by players.  The exchange rate floats based on supply and demand.  The upshot is:

• Completely free players (and I suppose anyone willing and able to play the AH for profit) can eventually acquire enough Zen to buy any item they desire from the cash shop
• Because people who are actually paying are such a minority, the supply of diamonds for sale is constantly increasing and thus the amount of diamonds a player can expect to get if they are willing to buy and resell some Zen are perpetually increasing
• $20 worth of diamonds almost always gets you more stuff and more interesting stuff than the $20 worth of Zen; also, the NPC prices aren't subject to inflation

It's an odd setup, but apparently players are more willing to tolerate this approach than having Cryptic cut out the middle man and sell the diamonds outright.  There's a niche for the clever, a way to monetize players who are never paying a cent of their own money, and a way for the player who does not want to be bothered to solve the problem with their wallet.  Clearly it's working for Cryptic well enough for the game to stay up and running.  Whether this approach can fly in the long run with inflation is another matter.