I do this occasionally but never did it in earnest for reasons I hadn't really thought much about until I read "A list of N things": http://paulgraham.com/nthings.html .

You can write the longest post ever but as long as it's well broken up and important parts highlighted/bolded you'll still get people commenting etc

I would tend to say that if some parts are important and others aren't, remove the unimportant parts until there aren't any left, then publish what remains. This is another practice I use, although sometimes with more success than others.