As an editor at a major publishing house, let me do so:

1. Unit cost. A print book and an ebook go through the same production process to start: copyediting, page design, jacket design (which includes licensing any cover images), page proofs, blues, indexing. I don’t include editing because that’s a different line on the p&l, as is marketing. The formats diverge when the pages are released to the printer as PDFs. Mercifully, all this is done digitally now.

The print book is printed, bound, shipped to one of our warehouses and from there shipped out to the chains’ warehouses, distributors and individual stores. Comp copies to reviewers and to, say, the editor’s friends also go out now, but again these are charged to publicity, although the additional copies do bring the print unit cost down. I’m not sure what line the authors’ copies go on.

Meanwhile the ebook goes through additional production steps: translation into ePub, Mobi and PDF (we may just remove our watermark), quality control (to make sure the ebook looks as good as the print book), then it goes to whatever service handles our ebook fulfillment, billing, etc. The ebook is then released the same day as the print book.

My point is, most of the component costs of a book’s unit cost are shared by the print and electronic version. The extra production costs for an ebook are cheaper, yes, than the materials and shipping used for print books. I wish I could tell you how much. But the unit cost for an ebook is not $0.00.

Let me add that ebooks are non-returnable, while print books are very much so. 40% of what we ship out, gets shipped back, and we pay shipping both ways. More costs against the book, but these aren’t part of the unit cost.

2. Marketing. On this line of the p&l goes catalogs (print and digital), signs at events, travel and related expenses, etc. The author isn’t charged, although authors are called on to do far more marketing now (if not all, in many cases) than before.

3. Agents. If the author is agented, we send the author’s checks, if any, along with a royalty statement, which they always get, to the agent, who then disperses the money to the author after taking his/her cut. Does every author need an agent? No. But an agent serves several valuable purposes: she understands book contracts and negotiate better than boilerplate terms, such as which rights the author should keep, in particular dramatic rights (many agents, in fact, have their own boilerplates with publishers, which they then tailor to an individual project); she can act as the author’s advocate so that an editor’s relationship with an author isn’t tainted by filthy lucre; she can explore other opportunities for an author (if we don’t have, say, world rights, we’re not going to sell translation rights for you); she can be a sounding board and therapist. Agents help editors too. When an author’s being an A-hole, we can tell them to kick their client in line without having to go to the a-hole himself. A very passive-aggressive business, is publishing.

4. Self-Publishing. I think lots of books can be easily self-published, but that supposedly extra money is counterbalanced by the author having to do all the work after he puts his pen down. In this way, self-publishing is less like authorship and more like a small business, in which there’s one product and the author’s also supplier and distributor. That doesn’t often get talked about. An author has to make a choice, then: does she want to write, or does she want to sell and look for time to write? For authors whose book is an extension of their existing business, they might as well self-publish. For authors who want to create, it might not be the best trade-off. After all, John Mayer, king of rock star tweeters, gave it all up when he realized maintaining his social media profile was sucking up all his time and desire to write songs.

4. Advances. Here’s another thing self-publishing advocates don’t talk about. One person in this discussion mentions it in passing, for instance. The fact is, half of all advances are not earned back. Which means an author was overpaid, but gets to keep the money. In defense of publishing, it might be better for an author to roll the dice and take the bigger check now rather than hope he can make it up himself in the long run.

5. Sales. People like to throw around big numbers, such as million copies. Do you know how many books sell a million copies a year in any format? Maybe 50 out of the, what, 250,000 published every year. If that’s your model for a self-publishing business, you might as well add a line for lottery scratch-offs to your p&l. The fact is, most books don’t sell more than a couple thousand. For example, for twenty years I’ve published trade science books: narratives, surveys, etc. The average net sales hasn’t changed a single bit in two decades, somewhere between 3000 and 8000. I just checked the Bookscan nonfiction bestseller list for this week, which covers hardcover and paperback. Only 48 books on the list have netted more than 70,000 copies (which equates to roughly 100,000 print copies actually sold) and only 19 were published this year. That’s not a large “epic win” ratio.

Bottom line: There are benefits to self-publishing, but whether an author takes this route or that of a traditional publisher, he shouldn’t expect to be able to quit his day job.