An eBook represents the most cost-effective way to get this message out to the public, and it is the content rather than the form which is important. On the positive side, it costs less than half the price of a normal paperback, requires no postage, and is immediately available world-wide.
On the negative side, you will find it difficult to read it in bed (you could use a laptop) or while commuting on the train. If you normally read in the loo, and do not keep a computer in there, the difficulty compounds. In that event, you have our express permission to print out a few pages for such use, providing they are destroyed afterwards, and not sold on eBay. Note though, that viewers now have the option of buying a printed edition.
There are two other reasons for publishing in this format. First, although I have had seven other books published, they dealt with the more marketable and less controversial concept of making money in the stock market. After shopping this one around a few publishers, I came away with the impression that although they liked the manuscript, they were uneasy with being associated with a book that challenged religion.
Second, it is much easier to update a PDF file than it is to make changes to a printed version, for obvious reasons. I'm always coming across new scientific facts, insights or new information. The eBook format allows me to incorporate these into the Guide with a minimum of fuss. This requirement also affects the printed version: by keeping to a small and limited print run, modification is more practical.
Finally, I should mention that I have had link requests turned down because this is judged to be a commercial site. As everyone realises, it costs money to build and maintain a web site. I could have requested donations instead, as so many other atheist and humanist sites do, but I decided not to go down that path. I make no apologies for selling the book as a product. It has taken several years and hundreds of hours to reach its present form. More importantly, I believe in the Ayn Rand principle of value in exchange, and I feel the book offers that.