Re niche. Yes, do you think the whole sales/marketing process was easier because your target market are quite narrow (ruby, UNIX, programming)?

Would you have priced differently knowing what you now know about discounting effect?

It's always easier to target an audience that you are familiar with and are a part of. Since I would have bought this book myself if someone else had wrote it I knew what people would want to know and how to reach them.

If I were targeting the book at sysadmins, for instance, I would have had no idea how to get in front of them or talk to them at their level.

re: pricing, nope. I think the discounting works because it's intermittent and gets people sharing. If I were to lower the price permanently I wouldn't expect sales to remain that high.