And how long do they last? I bought 1000 CSC today, and no stamp. Do they appear in your inventory? I could still access the reward card page without an error monster or anything, so I'm assuming it's still going on. How long to I have to fill it out, and where do I get my stamps?

You should have a little mushroom stamp up in the top left corner of your card. You only get prizes every 2000 CSC you buy, though (other than the forum title, which is on an odd stamp but I don't know which one).

Oh yeah! I did see that little mushroom stamp in the corner.

I do have another question though: how long does this last?

About 3 months, probably. That's how long the first one lasted and a staff member posted on the news post announcing the date for this card, that they're experimenting with ~3 month time frames. I don't think it would be any shorter than 3 months per card though, personally, so that's what I'd plan for.

3 months? That should be easy enough. Thank you. :)