Here is the easiest way to take advantage of the offers for the Easter event. The new dungeon release requires an e-mail to have been sent out, which contains the code. Luckily, this one does not.
First, go to mmosite.com and register. After registering, you should have an option to take a survey. It's short; a mere 5 questions without any real personal info required. This will give you 10 units of the websites e-currency: MMO gold.
After that, head over to the prizes section of the site. On the right hand side you will find a tool for exchanging MMO gold into "points" , with which you can redeem the prize packs. Your 10 MMO gold from the survey converts into 10000 gold, only 300 of which is needed to get the Shaiya package. At this point simply click on "Redeem" under the Shaiya button and it will present you with a code. Copy it or write it down and then go to the Easter event link for Aeria provided in the original post in this thread and enter your code.
The rewards (coming out to about 2.5 bil!) are listed at the bottom of that page.
From there... just check your bank.