Part of the problem is most organizations fall into multiple categories simultaneously.
Publisher ClassificationsTraditional Publisher: This is actually a term created by many subsidiary publishers to differentiate themselves, and for this reason it carries some bad baggage to some. For me, I tend to use this term for organizations that base their business model on the way publishing has general been practiced before the technological changes of POD (print on demand) and ebooks. I'll define a traditional publisher as an organization that focuses on the production of physical books (paper, also known as dead tree books) which are, by in large, sold through through retail markets both online and in physical brick and mortar stores. This type of publishing relies on a certain infrastructure which includes: large print runs (generally 1,000+ books), warehouse storage, and a sales model that focuses on large commercial buyers and acquisitions librarians. In general this type of publishing is practiced by larger organizations who can afford rather large initial cash outlays when bringing on a new title. In general these publishers expect authors to have agent representation and pay both advances and royalties.
Electronic Book Publisher: An organization that focuses on the production of electronic books, generally in a variety of formats), which are read on electronic devices such as dedicated readers (kindle, nook, kobo, Sony), general purpose tablets (ipads), sophisticated cell phones (blackberry and iphones), or computers. In most cases these books are sold via online retailers. These retailers can be focused on a single format (Amazon sells kindle books, Barnes and Noble Nook books) or provide a wide range of formats (Smashwords and Fictionwise). In general this type of publishing is practice by all publishers (large and small). Some indie publishers produce only ebooks, and in this low-overhead model, they can be more flexible than traditional publishers with regards to authors they bring on and therefor will often accept both agented and unagented authors.
Audio Book Publisher: An organization that creates and sells books that are experienced through listening rather than reading the words. An audio book may contain a single narrator reading all portions of the book, a full-cast where different characters are represented by different authors, or a full dramatic version which adds sound effects. These works are sold both in physical form (CD's) and electronic downloads (such as MP3's). Some retailers, such as Audible.com provide audio books on a recurring monthly subscription similar to how Netflick distributes video. Some sites, such as podiobooks.com release books serially (an episode at a time) and titles on this site are free, although they do accept donations. These serialized audio books are sometimes referred to as podcasts. In many cases the audio book is treated as a subsidiary right and the production of the audio book is performed in conjunction with a traditional publisher work.
Trade Publisher: An organization that produces books targeted to consumers. This includes both fiction and nonfiction and is inclusive of all formats: paper, electronic, and audio. Trade books encompass books for both adults, teens, and children. In general the only books that don't fit into this category are textbooks, and scholarly works, and books tied to a certain profession (such as medical reference guides for physicians).
Big-six Publisher: Due to consolidation in the publishing industry almost all of the names that are recognizable to an average consumer actually are imprints of one of six large conglomerates. The big six are: Hachette Book Group, HaperCollins, Macmillan, Penguin Group, Random House, and Simon & Schuster. Any publishing company that is not an imprint of one of these is defined as an Independent (Indie) Publisher.
Independent (Indie) Publisher: Any publisher that is not one of the big-six or one of their imprints. These publishers can range wildly in size from sole proprietor to large companies with millions of dollars in revenue. Indie publishers in aggregate account for approximately 50% of publishing revenue. Some self-published authors like to refer to themselves as "indie" to denote a mindset similar to indie bands and indie films. Since they are not a member of the big-six they can legitimately make this claim although many take offense to this designation.
Self Publisher: A person who brings to the market a book that has been created by themselves or a close family member (wife, parent, child). Self-published works have no third-party validation in so far as only the creator of the material has invested materially in the product produced. The self-published works may be created for no (or little) cost if the author takes on the full responsibility of production (editing, cover design, formatting) themselves. In some cases a self-published author will hire freelancers for these services. Alternately, a self-published author may utilize a Subsidy Publisher for the production of their work.
Subsidy Publisher: A publisher that takes a manuscript from the content owner and produces final products such as print books, ebooks, or audio books. In some cases, the subsidy publisher will merely create the files and provide them to the content owner for distribution. In other cases, the subsidy publisher will take responsibility for inserting the products into various retail channels. In most cases an upfront payment is made by the content owner to cover the costs of production. Furthermore, if the subsidy publisher performs distribution services then income from the sales will be shared between the publisher and owner. Subsidy publishers do not act as third-party validation of a work. They are vendors that will take a manuscript, regardless of quality.
Small Press Publisher: These are almost always independent publishers (see above) who generally have modest sales and produce a limited number of titles per year. There is no industry consensus on what those numbers should be. I generally classify them as under $500,000 in profit and 20 or less books per year.
Agent-Publisher: A person who performs both publishing services as well as selling rights to other publishers. Many agent-publishers focus on existing client's back list titles which have reverted after going out of print or are older such that never existed in electronic form. While there is noting preventing an agent-publisher from publishing new works, in any format. The most common scenario is for them to publish existing edited works in electronic formats.
Retailer-Publisher: An organization that functions both as a publisher and a retailer. There are very few publishing companies that fit this category, namely Sterling Publisher (Imprint of Barnes and Noble), and five Imprints of Amazon: AmazonEncore, AmazonCrossings, Montlake Romance, The Domino Project, and newly formed Thomas and Mercer. Retailer-publishers rely mainly on sales through their stores (both online and brick and mortar) and in some cases require exclusivity as a term of the contract. Retailer-Publishers may find difficulty having their products sold by channel partners as retailers prefer not to provide a revenue stream for their direct competition.
POD Publisher: A publishing company that creates its print book versions using print-on-demand technology. This allows books to be produced one-at-a-time once an order is placed. In general POD titles are not stocked in stores stores as they must be paid for prior to production. Publishers using this technology usually sell their printed books through online channels. Most copies sold through a brick an mortar store are special requests where a customer has asked to order a title.
Author Friendly Publisher: Any publisher whose contract deviates from excepted industry standards such that they provide more favorable conditions for the authors. This could mean providing contracts that automatically revert rights after a certain number of years, provide a higher royalty rate, or remove restrictive clauses such as options and non-competes.
Legacy Publisher: This is a pejorative term used by people who are generally embarrassing new technologies, such as ebooks and POD to refer to publishers that are operating much in the same way that they have over the history of publishing. In general what they are referring to are organizes that still focus on print and bookstore sales and generally write contracts that attempt to limit the rights of authors.