To my knowledge it is the most active site of its kind. I joined, but I haven't really found any use for it, but I am not currently in the job market or seeking to make business connections.

yep..this is a very good site for professional.

LinkedIn is a good social network where you can connect with different user having different stories,ideas and having different activities.

For business connections and referrals, it is by far the best site.

For business connections and referrals, it is by far the best site.