Just submitted a link once, didn't really subscribe but like I said, wouldn't say it was SPAM but it did catch my eye because of the co-op being mentioned.
I remember few weeks ago Shaw suggested sending info about the network to your link partners. So .....
Now you mention it, yes he did indeed, I remember that too. This happens to be someone from a directy, thus has many link partners. It'd be good if all of them signed up (and a nice referral bonus to P.C. too!).
I've gotten a couple of these via newsletters as well, but no real spam. The problem with this is that you don't know who is on your network that you're sending the email to. I completely screen the people I link to; and I wouldn't recommend them the network unless I would link to them myself. The last few link requests I've gotten have all been link farms basically and would not exchange links.