Some people seem to think Linked-In is for getting a job, not really.
Very similar to Facebook but based on work related and professional contacts.
Negatives, there is a premium so you don't get all features (it's not really a negative).
Positives, you get everything you need out of the site WITHOUT PAYING premium is only for those who are serious about LinkedIn.
Highly recommend for those serious about making business contacts.
You will get some people contacting you which will come across as spam, recruiters mainly for me, this is the same as anything nowadays.