Some people avoid buying a smartphone precisely because many carriers force purchase of a data plan. For example, Virgin Mobile USA offers pay-per-minute voice service starting at $20 per 90 days but won't activate that plan on a smartphone. Instead, plans that can be activated on a smartphone start at $35 per month, which is five times as much.

With a substantial transaction fee.

With a substantial transaction fee each.

With a substantial transaction fee each.

But then you have to pay hundreds of USD for an iPhone (or maybe one hundred for a compatible Android phone) and hundreds of USD per year to upgrade from voice-only cellular service to smartphone service. Or what am I missing?

Often, yes. Always, no. I've had three credit cards. None of them charge any interest because I pay in full each month with an ACH transfer from my checking account.

The currency or the car?

(In before "yes".)

C) Wants to pay with cash. This is common among children too young to have a bank account in their own names.
D) Is buying an item that's too heavy to ship affordably with UPS or USPS and already owns a truck to carry it home.

So would you agree with Larry Niven's assertion that "sufficiently analyzed magic" becomes indistinguishable from science? If so, then the only difference between science fiction and fantasy is how in control of their magic the magicians are. By your definition, electricity used to be "magic" centuries ago when Luigi Galvani and friends were doing experiments in "animal magnetism", and inheritance was "magic" before Gregor Mendel's pea experiments, and Dungeons & Dragons magic is "science" in the "Tippyverse" stories where spells are "trapped" in push-button devices that people use daily and people commute from city to city through teleporters.

Bingo. What science fiction and fantasy have in common is exploration of how a particular counterfactual phenomenon affects relationship among sapient beings.

Allen County Public Library (Fort Wayne, Indiana) had The Lord of the Rings in its "Science Fiction and Fantasy" section in late 1993. This was three and a half years before first publication of Harry Potter and the Philosopher's Stone.

An author could always be his own publisher, hiring an editor and having books printed through a contract printer. Or he could sign a time-limited contract with a publisher and have copyrights revert to him after a decade. Or he could license the rights to a publisher throughout the industrialized Anglosphere (US, CA, GB, IE, AU, NZ, ZA) but retain rights in the rest of the world, as the Authors Guild suggests. Or an author could sign with Baen, a publisher that not only specializes in speculative fiction but also "gets it" with respect to e-books. Baen offers e-books with no digital restrictions management, releases many of its authors' older works as free samples in the Baen Free Library, and even offers paid early access to the public.

If Amazon can't predict its actual cost per order ahead of time, it could be compelled to use a rolling average over the past few months (or, in the case of highly seasonal products, a more representative average) so that the average discrepancy trends toward 0 euros.

Is a merchant required to let a customer place an order even if the customer chooses not to place his billing information on file with the merchant for future orders?

Book sellers that group science fiction with fantasy follow Arthur C. Clarke's observation: "Any sufficiently advanced technology is indistinguishable from magic." Larry Niven pointed out the converse about sufficiently analyzed magic. I'd be interested in how you would rigorously separate these.

I understand what you're getting at: you're trying to avoid works of speculative fiction that take place in a so-called standard fantasy setting. But otherwise, it sounds like you're trying to distinguish "past" from "future". This is complicated by settings that are nominally soft science fiction but do not cross over with real-life history in such a way as to anchor dates. These include BSG ("All this has happened before, and all this will happen again" more than 150,000 years ago) and Star Wars ("A long time ago, in a galaxy far, far away..."). What opinion do you have about speculative fiction settings closer to the present day, such as "steampunk" (recent past) and "urban fantasy" (present)?

What compels an author to sell permanent exclusive rights, whether through assignment or exclusive license, to a publisher?

First, I was clarifying that the convergence of science fiction with fantasy is not the fault of book sellers but instead the result of a fundamental continuum between the two. Second, I was clarifying that unavailable translations are not the fault of book sellers, be they Amazon or brick and mortar, but instead business decisions made by authors.