Tokens and Coins explained

This is my explanation/research on the difference between online game currency and point system that is used by every major online games company out there.

Let's look separately at Game Points (Coins, chips)

..and Game Currency (Cash, Gold, credit, or "Tokens")
  

Game points; 

Or Coins; They are worth very little but can be earnt in the games. Usually low-medium valued shop items items can be bought with 'Game Points' (GO Coins), although there may be an option to buy these items with 'Game currency' too.

OMGpop also uses the term 'Coins':

..notice they must be bought with OMGPOP Cash (their Game Currency), that is not USD, but represents USD in their system that has already been purchased.

Also notice in the top left they have 'Balance' which shows I have never given them money (Game currency), but have been awarded with some OMGPOP Coins :)

Zynga do something similar, but they seem to have the currency/point system unique to each game, so cash and points are not interchangeable between different Zynga games (unlike OMGPOP):

..for poker, they call their points 'Chips' (and they call their currency 'Gold').

Notice they probably gave me 5 Gold (cash) for signing up, doubt that can buy you much.

However, I've earnt over 50000 Chips (in our case GO Coins). But I'll never be able to buy premium shop items with that, no matter how much I win.

Game currency;

This can be called gold, or cash, and this basically directly represent USD in the online games company's bank account!

They can never be earnt, only bought with real money. The advantage for the customer and the company is that they can be bought as a set of say £5, $25, $50, etc..

Usually some bonus will be included with bigger purchases.

All shop items can be bought with Game currency, and some items may be exclusively available only by paying with gold (ie they can never ever get this item from just playing the game, and must cough up the real money).

Here's OMGPOP currency:

..or OMGPOP CASH, as they call it.

Notice they are implementing 1 OMGPOP CASH = 0.01usd. Plus they are giving a little extra for your generous payout (which will go straight into OMGPOP's wallet). They are not loosing 7usd directly. It is an intensive to entice players to part with larger quantities of cash. Players don't need to keep getting out their wallets every time they consider to buy something, plus they are getting more for their buck for clicking a higher number.

In the end it promotes more spending.

Here's Zynga's Poker credit implementations for their various games:

and for another one of their games they call it something different:

.. Blast Cash? Whatever, its still represents money (Game currency) + a bonus for paying out a lot.

And is separate from their earn-able coins. 

Let's look at OMGPOP's shop to see how they are selling point items and currency items:

..and there you go.. The gold coin items can be earnt from playing the games. The green dollar items only if you have OMG Cash game currency. (no sign of USD here. By the way, their animated avatars are looking good!)

Somehow players get it. They play more, they can get free stuff. They part with their cash, they can get the free stuff much faster, plus have access to exclusive items.

And that's it. We need both Coins and Tokens if we want to be able to both reward players, and want them to part with their cash. They are two different systems with only a one way transaction path Gold to Coins, Coins can not be converted to Gold, and Coins nor Gold can be converted back to real money.