Initial client meetings: to charge or not to charge?

Saw a useful discussion between posts here (Build a Solo Practice, LLC) and here (Lawyer Profit Systems) about how to handle fees with initial consultations. I think they're both right...essentially I think it turns on experience and if you're not charging what might that "free" time be used for in the alternative.

I feel as if I'm right on the fence. I'm in practice for 4.5 years now...done mostly free consultations up to this point. I think for some "preferred" referral sources (i.e. people who are sending us a ton of business) I'll keep doing free 30 minute referrals...others I'm going to scale back on and start charging. Obvious exceptions are some of the contingent fee areas that I have no experience with but I think free initial consultations are common.

Mike Sherman over at Lawyer Profit Systems say always charge and once your book of business is pretty full I think he's right. Then if you don't charge you're essentially throwing away whatever your hourly rate is for this free consultation.