Jon's right in that the output from a digital mic isn't an analogue signal, and won't work unless the equipment is designed to use digital.
However, the use of the term digital as applied to mics is rather loose, and many analogue mics are described as digital if they are intended to be used with equipment that records a digital signal, even though the mic output and the equipment input are analogue.

Why? Some perceived sales advantage I suppose

Stu