The importance of white space

http://slingingthebull.com/internet-writing-how-much-white-space-should-a-writer-leave/\
" Readers can follow an author’s train of thought better if some rest areas are interspersed throughout the piece."
White space is the white between your letters, lines, and paragraphs. If there's a breathing space (for the reader) then the writer's thought can be fully understood.
If not----- the eye (and the brain) leaps, skips around and too much may be missed.
The article speaks to 'professional' writing---- but the same hold true for forum posters.