Meta-spam is the concept of using
email spam tactics to promote products that will, in turn, provide you, the
consumer, with ability to spam others more efficiently.
In general, these meta-spam emails offer CDs with millions of email addresses (such as the infamous millions CD) and they always are very clear about saying that there are no dupes!!!!!!.
Many meta-spam offers also include writeups on email spam laws, so you can figure out exactly how many laws you're breaking, from the comfort of your own home!
One meta-spam I got even offered me a free guide on how to set up one of those "opt-out traps", where people think they're opting out, but in fact they're confirming their address is active, so you can sell it other spam houses for a nifty little profit!
Mmmm...meta-spam.
Update:
I'm compiling a list of companies that vend these meta-spam epic compilations. Here's one, straight from the mailbox of me:
Cyber FirePower!
P.O. Box 4331
Chico, CA 95927
Feel free to spam them. Ask them if they want free viagra or perhaps get-rich-quick schemes. Tell them you got their email addresses from a compilation of 142 MILLION EMAIL ADDRESS! NO DUPES!!!!!