That site is junk
Its a social network for "professionals" so think of it as the linkedin of facebook.
The old company I did some work for pretty much demanded that I use it but I said no, there is no point.
I got a call from one of their account reps trying to push for me and the team of monkeys I was working with to use it, saying how companies are going to ban facebook and this is a great social network for professionals. Unless they have a way to plug into FB, Twitter or LinkedIn, there is a ZERO percent chance anyone will really use this unless they are forced