Contrary opinion, I hate LinkedIn's site and even though I'm connected to some colleagues and industry people on there I avoid using it as much as possible.

Some of this dates back to their repeatedly inventing new excuses to email me that I had to go and unsubscribe from, part is that I can't look at anyone's page without LinkedIn telling them about it, part is their finagling everyone signing up to give access to their Gmail contacts similar to Facebook's harvesting of user info.

I guess they're a competitor, but if they're not as bad as Facebook is it's only because they have less reach.