One (more) reason to shop at e-book venues like Smashwords is that you are generally allowed to read free samples from whatever you are interested in buying. Amazon allows prospective buyers a 10% free sample for all books. Smashwords, on the other hand, allows the author to choose how much of their hard work to give away free. Most go higher than 10%, and they should. Here's why.
As I mentioned in an earlier post, I am an inveterate blurb reader. If the description interests me and it does not have egregious spelling or grammar errors (one recently published book had a spelling error in the title--not only in the title field, but on the cover), I will download the sample. Two recent books--Shifting, by Miracle Jones, and The Ex-Pacifist, by Sarah Wilson, passed the sample test early. So did the series of hilarious short stories entitled Ueda Sensei Solves Crimes of Depravity and Perversity, by Robert Crayola. I happily paid for the remainder of those books. Last night, though, I was reading the sample from a book of mystery stories that had both positives and negatives. The setup was clever and interesting but the narrator was kind of a dickhead. Unfortunately, the sample ended before the first story did, preventing me from knowing how the story came out and, more importantly, how good a craftsman the author actually was. I opted not to buy the remainder. Another five or ten percent in the free sample and I may have chosen differently.
Some authors may decide that giving away more than 10% of their book cheapens it. Quite the contrary. In my opinion, the more they give away, the better chance they have to make a sale. I have always thought that the first 20 or so pages of Harry Potter and the Sorcerer's Stone dragged a bit. Rowling was new to writing and probably fussed over those first pages a little too much. Marilynne Robinson's fine novel Housekeeping, begins with a 30-page preamble that is somewhat less than interesting, yet the book--also a first novel--as a whole is first rate. I don't see any reason why authors shouldn't allow up to 50% of free material, or even more. The more a reader has invested in the book--the time spent as well as familiarity with the characters and the plot--the more likely he or she will pay to read the remainder.
The length of a book may influence the sample size, although it shouldn't. For a 200,000-word novel, 10% is probably enough to allow a buyer to make a decision. That's after all, about 60 pages of a printed book. Still, 100 pages would be better. Conversely, I have seen some books that are so short that a 10% sample only covers the title page and license notes. A sample will work only if it actually samples the work.
A minimum sample size, in my opinion, would include the following:
for a novel: at least two chapters.
for a book of short stories: at least one complete story.
for a book of poems: a sampling of at least 10 poems, unless the poems are extra long.
for a play: at least one complete scene.
for a book of nonfiction: the introduction and at least two complete chapters.
Authors are encouraged to experiment on sample size, checking their own work and making sure that their sample includes enough material. If 20% gets to within a page of the end of a chapter, make it 21%.
So the more you give away, the more you get. That's a pretty damn good exchange in these times. In fact, I have actually convinced myself to go back to my own books on Smashwords and up the free samples. Maybe you should do the same.