In 2006, the ideas contained in The Long Tail: Why the Future of Business is Selling Less of More were considered revolutionary. Much of the evidence presented seemed as though it conflicted with everything we had known about the principles of marketing over the past one hundred years, and yet we can see the results of these ideas everywhere today. Amazon, iTunes, eBay, Netflix, and countless other retailers jumped on this shift in the past decade and have done ridiculously well as a result. This book applies to far more than just online retail. In a world where search engines are major information providers, even non-technical people need to understand the value of the long tail. Yes, the most popular keywords have lots and lots of relevant results, but the specificity of search queries is what can drastically help people find what they are looking for. By eliminating the most popular results (think Walmart level), searchers can find specialty goods that surprise and delight them (boutique shops in a remote part of the world).
Thankfully, The Long Tail brings up examples from several industries, creating a better way for readers of all walks of life to be able to relate. Author Chris Anderson creates interesting comparisons between the real-world limits of shelf-space and the much broader storage spaces of the internet while still recognizing the benefits of brick and mortar businesses.
If you're involved in any sort of online marketing or search engine optimization, this is a must-read. The material is dated to some extent, but it works as a recent history book.