You know, there's a difference between what people should do and what people actually do. Yes, I suppose people should always read the Look Inside, particularly with unfamiliar authors, but they don't always. (Come to think of it, I don't always, either.)
On the other hand, back in the days when brick and mortar was the only option, did any of us actually stand there and read the first 10% of the book in the store? I read the blurb on the back and sometimes thumbed through it, but I never read 10% while standing there. Honestly, I would have been worried the store clerks would look at me like the kind of person who eats something while shopping, finishes it off, and then doesn't pay for it. (Fun fact: one of the Borders Stores I used to go to back in the old days when such places existed was loaded with people who did exactly that. They parked in one of the comfortable chairs scattered around the store or even, amazingly, in the cafe inside the store, and read whole books. I even saw people taking notes, like Borders was their research library. So I guess the clerks wouldn't have cared if I read 10% after all. Of course, then Borders went bankrupt...)
But let's think for a minute about another factor in shopping--time. Let's say you are a voracious reader who buys lots of books, but you aren't a speed reader. Particularly if you're looking at longer books, would you actually read the whole first 10% of every book you're considering? That could easily be fifty pages a book or even more. Put another way, how many people reserve a whole day to shop for books on Amazon? I don't know anyone who does that.
Yes, in an ideal world, people would be more careful about what they buy, but the time factor alone makes that difficult to achieve in real life.
I think we might actually be better off if Amazon clamped down more on serial returners. We know Amazon has from time to time, but I'm not sure how regular it is. That might be the most effective discouragement of people reading and returning (otherwise known as free KU).
