Analog inputs on CDP---?

What is the purpose of analog imputs on a CDP? I believe most come with digital imputs, but I have noticed some companies offer them as an option!
I know of a couple of CD players or external DACs that contain analog inputs. These units also have either a passive volume control or pre-amp section built into the unit. The analog inputs are provided for analog sources like tuner, phono stage, etc., and allow for a system that doesn't require a dedicate pre-amp.

I've owned the Musical Fidelity CD/Pre and I've owned the Monarchy Audio Model 33. Both provided digital and analog inputs and allowed me to have a system that did not contain a dedicated pre-amp.