Signed up with a test account to see if there was anything to vipsecurity's spam claim.
If you sign up with them, you automatically receive email notifications when someone posts to your profile, sends a private message or network request, and also site updates. Those email notifications can be turned off in account preferences.
I don't think those email notifications can count as spam tbh. Atleast not in wikipedia's definition of the term.
[-The only reason I did not give a "useful, informative" rating is because I really can't judge it, as I'm not in the industry. It may very well be a useful site to people in the field.-]
Added note 2012-04-23: Their privacy policy is problematic at best, though. They basically openly admit they may sell your information to 3rd parties. I'd be careful with any personal info I'd provide them with. Thus changed my comment rating to "Ethical issues".