Aion is well known for its popular events that often provide players with shockingly high-value items.
Events that take place during various holidays such as Christmas, Haloween and Valentine's Day, in Aion, often bring some rather amazing rewards that can be obtained by chance. In many cases, players have the opportunity to obtain Mythic items, tons of Ceranium Medals, huge amounts of Abyss Points, Godstones and even +12 Plumes.
These events enable players to make shockingly high amounts of Kinah by selling the rewards, and also brings huge profit to the publisher because a wide range of event-related items are sold in the in-game store during these times.
During the previous Shugo Tomb event, I was able to make roughly 3-4 billions of Kinah in just a bit over a week and I probably could have made more if I had invested some Kinah into reset scrolls and chest keys, and it also provided me with so much AP and medals that I was able to purchase a whole AP set. This seems slightly overdone to me, because, in many cases, characters above level 30 can participate in events, and players often level huge amounts of characters above 30 just to get more out of the events. Plus, if new players who happen to be above level 30 are given the chance to make billions of Kinah, that kind of ruins the whole "newbie" experience.
There are two major issues with these events, one of them is the fact that they often provide items that are too valuable and yet when half of the server obtains them they will cease to be special and hard to get. The second issue is the fact that the publisher sells a lot of event-related items for real money, such as the snowflakes during the Christmas event, which seems like a rather disgusting act.
Aion is already well known for providing players with some shocking advantages for real money, such as the Arena tickets and Katalamize reset scrolls that basically enable players to gain Honor Points at an extremely fast rate, and the event sales do not improve their image.