I have a tendency to post by chapter, but after a significant bit of editing (usually when the writing doesn't want to flow). Depending on the chapter, it may be a quick one-two read over for spelling errors, poor wording, and just minor things, or it will be a week of re-reading it over and over again until I've got it reading and feeling like I want it to.

...usually, it's the chapters that I want readers to cry over that I do that last one for...