I generally tell people that from the research I've done, CIO doesn't seem like the best way and actually seems harmful (this is very far from my actual opinion, CIO horrifies me and makes me want to vomit when I think of babies crying in distress all alone...but I don't say that). And honestly, the little bit that seems to make an impression on ladies, is when you point out that the concept of object permanence doesn't set in until kids are 18-24 months. If you are within sight, they think you are GONE. They don't know you're standing in the doorway, or listening from the next room. They truly feel alone. That's why peek-a-boo works - they can't see you, you're gone forever...then poof! There you are again. A surprise every time. Anyway, they "learn" that at nighttime, they don't have a mommy.
Someone suggested Ferber to me on Facebook a while back...I just said that it would be hard to Ferberize a baby who sleeps in your bed! And left it at that.