This is an interested one. I've always liked to be very private with my writing, up until the point when I have a first draft completed.

Interestingly, however, I have just begun posting a novel (that has been in progress a while and become stalled) in instalments here on Medium and I find the mere fact that it now has an audience, albeit a small one, is really concentrating the min d and inspiring new character/plot directions.

I actually like that the audience, such as it is currently, is anonymous.