The major difference between a search engine user and a niche focus community member is this :
A search prospect May or MAY NOT know what they find when arriving and might not find what they truly want.
A Niche focus community member has a clear understanding of their community needs and discussion topics, and when invited directly to your relevant ebook, the gap between needs and desires are shorter and the resistance is lower.
PLUS when a search prospect finds Your ebook MOST platforms make it impossible to share with their communities, while when inside a community the word of mouse is inherent and almost seamless.
So if You wish to have a more receptive market, more follower potential, and the most important, an appreciative readership, consider developing a niche marketing campaign.
And then we have the Ebook4Good edition which comes with Hangout support here http://bit.ly/SocRespEbook2013
Or As a Gift For Your Socially Aware Community Writer, Author, Self Publisher or Activist http://bit.ly/EbookNicheGiftSW2013
Please consider joining our Google + community for weekly Hangouts4Good http://bit.ly/Ebooks4Good