The answer varies greatly on the actual contest.

As said in the contest FAQ:

"How to claim your prize

1. Some prizes will be confirmed via email (contest@mmosite.com).

2. Some contest will have winners' entry page for MMOsiters to claim their prize.

3. We'll send the email to you if you win.

4. Mostly you have to claim your prizes in 48 to 72 hours after the winner list announced. Otherwise, we may have to cancel the prizes or give it to the runner-up.


Prize Delivery

1. We will send your profile to the game official ASAP after we get the info from the winners. It may take a few days for you to get the prize.

2. For virtual prizes, the profile may including your Game ID/Login name, Server name, Ingame character name. The game official may put the prize into your inventory ingame. Do not be online 24/7, the game official may not have chance to put the prize in your inventory.

3. For real goods, the profile may including your real name, postal address, postal/zip code, and contact phone number. The game official may deliver the goods to your home direclty. They'll pay the delivery fee, but they may not pay for the tax or other fees.

4. All your profile will be keep in a save document then send to the game official only. Remember we will never ask your for password, due to the privacy."

Events hosted by MMosite usually have prizes either given through the winners' entry page or through e-mail. Where as the larger events hosted by other gaming companies would require you to give your game information to gain your reward (for events including rare/uncommon prizes). For those events with common in-game item rewards and in-game currency (beta package, newcomers package, etc.) you follow the directions on the Mmosite event page to gain that prize.