Other than an occasional "see updates from Drac von Stoller" notification and depressing "your profile appeared in '1' search this random time period" messages that showed up in my email inbox, I did not receive anything from LinkedIn; certainly nothing that furthered my "professional career." Of course, I put absolutely zero effort into maintaining any kind of updated LinkedIn profile. I don't really have an "online profile" of any significance; or at least, no online profiles on the standard online profile sites: Facebook, LinkedIn, and Twitter.
Anyway, I've grown weary of those depressing "your profile appeared in '1' search this random time period" messages, and have deleted my LinkedIn account.