[quote name='RabbitSuit']^ What he said.
I don't understand how to unlock the upper levels. I put in three codes, but I still only have lvl 1 items available. And the official FAQ doesn't exactly spell out my mistake. Do I need to use a specific kind of code?[/QUOTE]
Just a guess, but maybe the reusable ones don't boost your level? Maybe the one time use ones only work. I can't say for sure, I missed out the previous contest.
EDIT: The site runs pretty smoothly for me, but it will crash if I copy/paste anything.