It's literally right at the top of the newsletter... Next to the picture of the game cases. Under "Enter this code." Where you would expect to find a code.

If you have just white space, right-click it and click "show picture."

And to your earlier space question: 1935 "blocks" (god I hate how they explain space on the 3DS... just freaking giving it GB or MB Nintendo.)

Mine is just a grey box.

You're blocking it somehow, mate. Find somewhere else to bring up your email.

...*sigh*
Looks like i won't be getting that demo after all.

I would have an extra code to give to someone but mine won't show either.

Lots of people are having issues with the code. Just hard refresh and be patient.
Also, if you get a blank white space, wait for an image to pop in before you panic. Took me 5 minutes for my code to appear in the email. Took my friend an hour.

I pretty much gave up after refreshing the page for an hour.

All I'm saying is don't refresh if all you see is the blank box.
Only if you get an image error, "Coupon", or "Live Content."

Coupon is what i got all the times i refreshed. Except one time when they're was no signal so all i got was a blank area in that part of the letter.

Waiting for the servers providing these codes to stop crapping all over itself so you can get your code with ease and use it is preferable to adding more traffic by constantly refreshing when the system is already as taxed as it is because Nintendo can't into online services. It'll work later and you won't lose your code.

Bright side, you guys are still a step ahead of me, as I've yet to receive a newsletter and am thinking I might not get one at all. On the bright side, I'll probably have the Nintendo Network ID giveaway arrive with no issue in a week, because it's attached to a wholly different email service.

I know you got the email anyway, but this giveaway is entirely separate from Club Nintendo.