Microtransactions are small purchases made with real currency within a game. They feature most prominently within free-to-play titles as the primary business model. Microtransactions are often used to purchase in-game currency, which can unlock various in-game boosts to save time or unlocks.
Microtransactions differ from downloadable content in that they are not used to purchase additional content.
Microtransactions can be used to purchase Gems. Gems act as an alternative to Mythril, in which 100 Gems are as valuable as 1 Mythril. This means 100 Gems can refresh the player's stamina, refresh the party in between battles, and revive a KO'd party. Gems can also be used to increase stockpiles of equipment and draw from rare Relics.
Within the game it is possible to buy Gil with real currency. Gil can then be used to buy Crystals that allow the user to play a match (one per Crystal). For both Gil and Crystals there are four options of increasing cost for a better trade ratio; in other words, the more one pays at once and the more bonus in Gil or Crystals will receive.