I agree, it's not a virus - it's a trojan!

While their marketing may be "viral" It doesn't actually spread itself to other computers (maybe that's for the next version ;-)

Anyone bothered by these emails should send a complaint (with the original message and its headers) to swapnut.com's hosting provider which seems to be...

abuse@qwest.net

(at least they own the netblock). I bet their TOS has provisions against promoting sites via UCE (and make no mistake - this *is* UCE since the person getting the email didn't ask for it).