Today, most popular ebooks are sold with DRM protection which is usually applied by retailers at the insistence of publishers and authors. There are several DRM systems in use. The most common systems used with ebooks are:
- Apple Fairplay DRM, used only with Apple's products
- Amazon DRM, used only with Amazon products
- Adobe ADEPT DRM. Adobe sells its Adobe Content Server technology to anyone who wants it so. Its use is widespread and it has become the de facto industry standard.
As well as restricting users from copying and distributing the entire ebook file, DRM can:
- Limit the number of devices a user can load their ebook onto (typically about six)
- Time-limit access, eg for library lending
- Restrict printing or copy-and-paste
- Provide a limited lending facility, e.g. to lend an ebook to a friend
DRM makes ebooks more complex to use and to sell, making it unpopular with consumers and limiting publishers' options to sell ebooks.
But behind its use is the legitimate concern of many publishers and authors that books could follow the fate of music and other digital media in suffering from widespread piracy. DRM also allows libraries to lend ebooks by managing the loan expiry.
For each of your titles, you'll have to decide whether to use DRM. As well as giving (some) protection against copying, DRM will affect where your ebooks can be sold. DRM is usually applied by the retailer and requires complex and expensive technology. This makes it difficult if you want to sell your ebooks through smaller players such as local booksellers, bloggers or, indeed, your own website.
But DRM can be implemented in a way that makes it simple for the user. A good example of this is Amazon's system, which is so well integrated into the user's overall experience that most users are probably unaware of it.