Do ebook copy protection schemes work?

I actually don't know the specific details of most of the technologies these services use, but I can speculate. However I'll admit that, even though they annoy me, I have on occasion purchased ebooks of this ilk, so I do understand the user experience.

From the customer's point of view, they typically download the ebook in the form of a "setup" program. When they set it up, they're required to enter a serial number or activation code that they got at time of purchase. The setup program then encodes some information into the ebook itself that only allows it to be read on the particular machine that it was set up on. If you copy the book or the software that's used to read it to another machine, it simply fails to run.

Some systems allow you to run the setup on more than one machine, so that book might be able to be installed on more machines, as long as you have the activation code. Others check to see if that activation code has already been used, and will deny any setup other than the first - unless you purchase an additional code.

I can think of several ways to tie an ebook - or any software - to a particular machine. In fact, it's something that we've seen Windows itself do, as well as Microsoft Office.

Regardless of how it's done, copy protecting ebooks has several pitfalls. Some are technical in nature while others are usability issues.

• Most copy-protected ebooks require their own reader software. That means in addition to downloading the book itself, the customer must download and install software that's used to actually decode and read the book. At a minimum this is an annoyance for many customers, and often a source of compatibility problems. Personally I've found those dedicated viewers to be less polished and powerful than more common tools such as Adobe Reader. It typically also means that the reader software needs to be produced for different platforms (Windows, Mac, Linux), or you as the author must explicitly decide that users of some platforms simply cannot read your ebook.

• "Regardless of how it's done, copy protecting ebooks has several pitfalls."

  Ebooks that are locked to a single machine are frustrating, at best, for customers such as myself: I have several machines, and I may want to read the book on several of them at different times. Perhaps on my desktop with its larger screen when I'm at home, perhaps my laptop if I'm traveling. Heck, perhaps even on my PDA if I'm out and about. Customers are typically not willing to purchase the book multiple times for that flexibility. I know I'm not.

• Most copy protection schemes can be cracked. It depends on the type of scheme, and the dedication of the cracker, but there's no guarantee that your book will never be stolen, even if you do use a copy protection service. None are perfect.

I see strong copy protection as a disincentive for customers to purchase your book. It places barriers to reading your book, makes the experience less flexible and more cumbersome.

If I could influence you with my preference, it would be this: publish in unrestricted PDF. Or, if you must, publish in PDF with a single password (no per-user password, just a single password that will open any copy of the book). Place a strong statement at the beginning about theft, and leave it at that.

From what I have heard from ebook publishers, the loss of sales due to theft is often more than offset by the additional sales from using a standard and flexible format, plus the additional sales that are generated by any "word of mouth" sharing. Many honest people actually decide to purchase the book - if it's good - after they've received a bootleg copy.

Naturally, your business needs and your understanding of your customer will determine what's appropriate for you. The technologies can certainly work if you decide that's the direction you want to take.