TERA is an MMORPG, launched last year features quests, crafting, and PvP is now totally free! There is no level, time, or content restrictions. The game will be re-launched as Tera: Rising in February. Game developers do need to eat, and that's where a cosmetic/convenience-focused store enters the picture.
"For those who want to customize their characters and stand apart from the crowd, the En Masse store will offer an even wider array of costume and customization choices. And for TERA players who want all the extras, there’s elite status, a purchase that offers 30 days of extra dungeon rewards, 10 bonus daily quests, a daily delivery of items and boosts, an elite mount, in-game store discounts, reduced brokerage fees, and more."
The game got 7.7 metascore and sold pretty well last year but I think they have to opt for the free-to-play system because of World of Warcraft and Guild Wars 2, which are the best in the MMORPG genre.