1.) To desribe how much you enjoy spam ham.
2.) An sarcastic way of saying your pissed about your junk mail.
3.) Just another way to say "Cool" or "Awesome".
2.) Matt opens his e-mail to find 4,294 new messages in his inbox. Sarcasticly he utters "Spamtastic".
3.) Kyle: I just found $100 under my bed!
Origin: Spam ham, a canned meat product sold by the Hormel Foods Corporation.