There are many reasons for using a unique identifier for an e-book. It helps with discoverability and allows you to separate out the different formats of the title, which in turn allows you as a publisher or writer to see how it is doing in various channels. The ability to measure the success rate of each e-book format for any given title is paramount to good marketing. The ISBN also gives you control over your title and your content. If you let someone else assign an identification number to your content, you lose that control, both in terms of quality and ownership…There are a variety of reasons to add the ISBN on your own as well, either as the author or publisher; one very important reason being that if you don’t assign an ISBN, the distributor could assign one for you, which could result in multiple ISBNs for the very same type of file (as sold through a wide variety of distribution channels). The bloat is likely to make collating and tracking sales data –- and thus looking at overall performance for a title — all the more complicated.Though, as discussed here, there is no universal answer as to whether or not each format requires individual ISBNs, one thing is indeed clear: take control of the process. The worse thing you can do is lose control of your content or let another entity (whether conversion house, distributor or retailer) control the metadata and, accordingly, the invisible ties that bind you to your customers. Ceding too much control takes you out of the picture and makes this already complex situation all the more challenging. (via publishingperspectives.com)
Erik Christopher’s article got me thinking… I know nothing about ISBN numbers. Onward march!