the link to the Helicopter thread. Sometimes fortune bags are only in the website item mall (not in-game). They often have a few things that are on one or the other, so just keep checking the Promotions
section of the forums to keep up-to-date.
Mounts are also often in tiered spenders where if you spend a certain amount of AP you can get mounts, costumes, and useful items depending on how much is spent. For example Here's
the link to the last tiered spender that ended on the 12th.