When it comes to book discovery and retail search, traditional publishers have two advantages over indie publishers.
The first is the ability to add more keywords to a book. Most independent authors will be able to add 5-7 keywords to their book's metadata. Each keyword (or phrase) provides an opportunity for the book to be matched with more search queries. The more search queries a book matches, the more times it will show up in search results, which of course means an increase in the potential customers who will see the book.
How is this possible?
Each online retailer (such as Amazon), accepts book metadata through different channels, and processes it for the search engine to use. Most independent authors add their data through a website (such as http://kdp.amazon.com). These websites are coded with specific rules about what data can be added and restrict, for example, how many keywords can be entered. (This is necessary to ensure a minimum level of quality in the data, which can impact search results).
Publishers, on the other hand, typically send book metadata to retailers in bulk, using an industry file format called ONIX. Under the ONIX standard, the keyword field has no restriction on the number of keywords that can be added to a book.
Practically speaking, adding a very large number of keywords will lead to limited discovery benefit, as each online retailer will parse and process a maximum number of keywords.
But retailers almost certainly accept more than 7 keywords. The ONIX standard recommends filling the keyword field with 250 characters. The BISG working group, dedicated to book keyword best practices, however, recommends using 500 characters. This working group comprises members from Amazon and Barnes & Noble, the consumers of this book metadata, who use it in their search engines (we covered this group in our last post). Given this recommendation, and the contributors behind it, it's unlikely the book retailers would restrict keywords to less than 500 characters.
So how does this compare to the 5-7 keywords self-published authors are allowed? 500 characters equates to approximately 80 words, which is at least 27 keywords (phrases of 3 words in length - or more if keywords of 2 words are included). This is almost 4 times as many keywords.
Isn't having too many keywords bad for SEO?
Retail search engines process keywords from metadata in a structured manner (as opposed to web search engines that extract keywords content like web pages), and are unlikely to be subject to keyword dilution, which is the idea that using more keywords reduces an individual keyword's value. Keyword dilution can be a problem for a web page, as the breadth of topics a web page covers is likely to be less than an entire book.
It makes sense to use many keywords to describe the many topics in a book.
Does all this equate to a discovery advantage?
It is highly likely. If you use one keyword, your book will be matched to related search queries about that one topic. If you use 20 or more keywords, your book has 20 opportunities to be matched against different types of search queries, therefore significantly increasing the number of customers likely to see the associated book.
Better Search Data
The second advantage for publishers, who publish on Amazon, is data to help with Amazon SEO. Publishers with a high enough sales volume, will be invited to apply for access to ARA (Amazon Retail Analytics) which provides insight into search queries used by customers on Amazon. Core to any effective SEO strategy is the ability to evaluate and assess different keywords (search terms) for search volume (this is what Google Analytics provides free). ARA provides this data, albeit in a slightly obfuscated value called 'Search Frequency', along with data about conversions. Access to this data improves the efficiency and accuracy of keyword selection, as it allows publishers to determine whether to apply a long or short tail keyword to a book (depending on it's sales rank), and also to assess the type of books that convert the best for each search term.
We can speculate why these differences exist, which are likely rooted in the history of traditional publishing and of self-publishing. In the early days of self-publishing, independent authors were much less sophisticated than they are today, as were the service providers to help them publish. It's likely disparities such as these, that provide considerable advantage to traditional publishers, will become less pronounced as the self-publishing industry matures.