There is a big differene between spam and invites (same principle as gmail invites or viavites in essence) I believe if you have a good enough product and can actually offer the person you're contacting something of interest to them then no harm done.
Creating bulk e-mail lists and sending the same messages over and over again is a different matter altogether though! Generally speaking, If i'm browsing the net and come across a designer I like or someone with a large amount of knowledge I contact them and "invite" them to talkfreelance, 90% of the people I have invited thank me.
Very interesting to see people are actually coming here through google! What term did you search for? Also, Never thought my campaign at tutorialman.com had any effect at all, good to know! Keep the replies coming everyone, very helpful for me (in terms of advertising methods)