I think I know what happened and why you are probably getting spam. When you fill out the offer, they start throwing questions on single pages at you about signing up for OTHER lists with a vague text above it saying something like "to continue, click yes" or something like that. After about 4 of these, I gave up ... realizing that the original ipods page was still in the back and done... I had just been needlessly signing up for shit.
So at the very least, I am one of those that didn't go through with it
I did click the unsubscribe link on a TON of the spam, and it seems to have reduced it to a trickle. I haven't done the unsubscribe thing on the rest yet, i just forwarded my mail to a gmail account and it has cought all the spam nicely.
I had trouble giving away 6 free gmail accounts, everyone already had one... so I doubt I would have any luck with the ipod thing