I was doubtful about drawing attention to spamming and when I posted Kammer's message on Usenet I removed all references to spam. If the message just says "are you aware that..." people will either be sympathetic to it or ignore it; only a very small minority will be offended by it. But if the message starts by saying "this is spam and we know it's wrong, but were doing it anyway", then you have stacked the deck against yourself from the outset as evidenced by Paul's reply.

If I send a message to a colleague or friend that he's not expecting, is that spam? No, it can't be, otherwise how do you ever initiate any dialogue? It's only spam if you bulk-mail it to unknown recipients. If everyone on TMA emailed a (personal) message to each of their colleagues and friends and encouraged them to follow suit, you would have the effect of pyramid mailing, but without the illegal pay-back aspect.