Originally Posted by gmw
I think it is very likely that existing ebook DRM solutions will cause more harm to the audience you actually want, than it will provide benefit to you against pirates - even in a specialist market.
More, in a specialist market. Strong prevention of casual file-sharing guarantees that nobody *joins* the target specialist market in order to get this book; people who might be interested are dissuaded by extra hoops and hassles.
And making casual sharing difficult does absolutely nothing to dissuade large-scale piracy; all it takes is one dedicated person with screencap software--or a willingness to type--to create a sharable text version. And if it's much easier to deal with than the official version, it'll be shared even by people who have bought a legit copy.
If the target market is students, that's a crowd that traditionally has high technical skills, lots of free time and imagination, and low money--a combination that leads to pirated content in several media. If the target market is industry professionals... if they have interns working for them, that's about like students. It just takes one boss saying, "get me a version I can read on my Kindle. Sure, take a couple hours of overtime for it."
Annoying DRM encourages workarounds. The reason there isn't more for the "ultra-secure" ebooks is that mostly, *nobody cares.* If someone does, they are no harder to bootleg than the Harry Potter books, which had no ebook version (and therefore, no DRM) for years.