The sneak preview: Does it hurt or help?

A little exposition is in order.  I wrote and developed my first two novels chapter by chapter, posting them on my deviantArt page to gauge the opinion of the community there.  At the time, while serious as to writing professionally, I was unsure if I really had something people would like, so it seemed as good a way to any to look.  Despite being entirely original works with no basis in any particular fandom (a popular thing on dA), I acquired a fair number of regular readers and even some amount of community goodwill.  I obviously had something worthwhile, so I finished, edited (something I have learned that I need even more help with), and published.

 

So here are is the question:  Did having the rough manuscript, chapter by chapter, already out in the public hurt me?  How many people were content to simply copy and paste it into a book?  How much, if any, of my subsequent books should I post for free?

 

Instinct makes me think I should at least post the first couple of chapters as teaser material.  Whet the appetite of the public and all of that.  Even that, though, I remain unsure on.

 

If you’re a writer and you read this, hell even if you aren’t, what do you think?