Linked In 

I haven't signed into Linked In for over two-three years.  I get tons of emails from them, some of which I wouldn't mind checking, in theory.  But they all require me to sign-in, which I don't want to do.  Linked In was my foray into social networking.  Dipping my toe in before signing up for Facebook.  Basically, as far as I can tell, the thing is basically spam.  Any pertinent information could be easily emailed to me by my Linked In contacts if they wanted.  But they don't want to.  Linked In basically spams on behalf of you.  Am I missing something?