LinkedIn vs. Facebook

I'm involved in several business ventures, so I'm kind of taking an observational position on what works best.  :-)

It seems to me that, in general, Facebook is usually good for B2C businesses to find individual clients and customers, while LinkedIn is good to network with other professionals, obtain referrals, or for B2B businesses.  Has this been other people's experiences?  Have you found clients from direct contacts on LinkedIn, or is it more of a referral network?

Thanks!