Location: Jerusalem , Israel
let me comment on that :P
dont listen to all of the above (from my point of view).
you could make a nice income from this.
1.choose and class your audience
2.market to this audience only
3.give samples (chapters) to read in site.
4.do not sound cheezy ("lifetime opportunity ..")
5.good design - trust able site
and from my opinion you should raise the price, thats how you create liability .
believe it or not, people like paying.
now a little cmnt for kline11.
i could get ANYTHING for free in the web.
i could get any app for any device for free
like most of the people you know right ?
OK, that dosent mean that the other 1Billion people do that .
in the contrary , people buy like there is no tomorrow!
another advice, translate! niche e books could fit overseas countries (Europe especially) and the same kind of audiance you cannot reach, in other language !
my last and best advice is optimization and positivity .