This is spam in the truest sense of the word, and I resent it. At worst, the site admin is trying to solicit membership by grabbing e-mail addresses from mailing lists. At best, the site allows for indiscriminate signing of of e-mail addresses with no form of verification in place to attempt to prevent this sort of thing. Either way, in my opinion, the site is responsible and needs to be held accountable for the e-mails I received sent through them. I don't care if this site is the best thing since sliced Coke, if they are not going to behave responsibly, then they need to be taken to task. If I had received a personal e-mail asking if I would like to join, that would be different. But the nature of the e-mail clearly indicates that it was automated, and so I will not be giving these people the benefit of the doubt.
I also hate teh term "blink". To me, a blind person calling him or herself a blind is the equivalent to an African-American calling him or herself by the N-word. I know not all blind people agree with me, and that's fine, this is just my personal opinion.