Free To Play
No up-front purchase required to begin playing
Minor DLC with no randomization involved. New items, equipment, abilities, etc.
Infinite Money Hole
No upper limit on in-game purchases
But First, You'll Need A Contract
A game-specific paid subscription service
There are three ranks of paid memberships which are required in order to create more than one game, play games with paid access (using in-game currency) and create groups.
There is an in-game currency that is required to purchase any avatar cosmetics, upload icons and thumbnails for your games or play games with paid access. The only way to earn this in-game currency is by purchasing it alone ($5-$200) or purchasing a membership which will allow you to earn a specific amount daily.
You can also find physical cards with scratch-off codes on the back ($10-$50) in multiple retail stores that you can then use to purchase a membership or in-game currency. You will also be rewarded with a cosmetic item when you redeem the code.