(I'm going to try to keep this post a wee bit shorter than the preceeding ones, because they're eating into my writing time and, as Rule 2 of being a successful author goes, "paying words have priority". Rule 1 is "don't die", in case you were wondering. Not many people break that one and prosper.)
In CMAP #3 I dissected a book contract for the sale of US and North American English language rights. As you probably guessed from the words in front of "rights", other stuff gets sold separately by authors who have any choice in the matter.
There are generally two other lumps of English language rights you can sell; "British and Commonwealth", and — if you can crowbar them out from B&C — "Australia and New Zealand". (These latter are most often sold separately by Australian/New Zealander authors. Those of us in the UK tend to find our UK publishers take a strong proprietorial interest in them; and as they're not worth a huge amount, it's not worth fighting over unless you've got a specific reason to think you can exploit them effectively.)
"British and Commonwealth" may or may not include Canada (see comments under CMAP #3) as a listed territory; it does cover just about everywhere the British flag flew over at the end of the 19th century, including Ireland, large chunks of Africa, and so on.
I'm not going to anatomize a British book contract separately here, because it's broadly similar to an American one. There are differences in the boilerplate legalese, due to the different legal frameworks for copyright and insolvency law, but the outline shape is broadly similar. There are a couple of significant differences, though.
Firstly, there's no mass market channel in the UK. There used to be one, but I'm told it disintegrated at the end of the 1980s; since then all books — including all C format paperbacks — are sold as trade books (i.e. unsold stock are returned via the wholesaler for credit, rather than having the covers stripped).
Secondly, the B&C market is smaller than the US market. The UK has a population of 62 million. Add Ireland for another 5 million. If you add in Australia and NZ you can add another 21 million. If the British publisher bags Canada, that's a whopping 40 million more ... and you're up to a core market of nearly 130 million people, plus loose ends elsewhere in the Commonwealth. So it should come as no surprise if I tell you that my B&C book advances are typically around 40% the size of my US book advances.
(This is why, despite being British and living in Edinburgh, I work with an American literary agent and prioritize the hell out of my US sales — the USA is the single biggest market for written science fiction and fantasy right now, with the B&C rights a long way behind in second place.)
Note, however, that this isn't where the buck (or book?) stops.
English is one of the top five languages spoken around our planet, but it's not the only one. If you write commercial fiction in English you are in an excellent position for having your work translated into other languages and sold, because there are generally more translators of English into [insert language here] than there are translators working between other non-English languages (if only because English is so widely used as the tongue of science and commerce). And you're able to show foreign publishers English language sales figures before they stump up the cost of a translation.
This works the other way, too. For example, Germany has a population of 80 million; add other German-speaking nations and groups and you've easily got a linguistic group the size of the B&C market. Nevertheless, there are only around half a dozen German full-time professional SF/F authors ... just one of whom earns a living writing SF. It's hard to sell a non-English-language work into the Anglophone markets, because editors are already surrounded by a plethora of home-grown talent without the need to commission an expensive translation. So we see very little German SF and Fantasy in the British or American markets.
The contract stuff:
In general, a translation book contract is a lot shorter than a US or B&C book contract. The rights being sold are: the exclusive right to translate the work into a given language, and then market the translation throughout the designated territories. (This may be within just one country, or it may be in the given language throughout the world. And it's complicated in the EU by the existence of a single market — the EU is effectively a single territory, so selling exclusive German language rights to a publisher in Munich implicitly precludes selling those rights to an Austrian publisher — they're both German-speaking nations within the EU.) There's usually also a set duration to translation contracts; it's very hard for an agent in the USA to track whether a book remains in print in the Czech Republic, so rather than a clause to permit rights reversion if the book goes out of print, we sell rights for a set period (typically five years).
My books are usually sold into foreign markets after they are published in the US and B&C markets, on the basis of reviews and sales figures for the English markets. The foreign publishers then need to pay a translator (typically on a work-for-hire basis) for the 6-18 weeks it takes to translate a novel. The success of a translated author lies entirely in the hands of the translator — if your translator is no good, your sales will tank whatever you do. So, if you're an author? Encourage your translators to bug you with questions, and be nice to them!
On the sale side, things are handled by my agent. They deal direct with English language markets and some foreign publishers, taking their usual 15% cut; for other markets (notably Russia, China, and Japan) they deal with a local literary agency, splitting a 20% cut. (That's 20% of a chunk of money I wouldn't have at all if they weren't getting out and selling the books ... as opposed to the 50% cut usually taken by publishers' rights departments if you hand your translation rights to your US publisher.) I'm not going to get into the topic of dealing with foreign income tax authorities here, other than to say that if you are every lucky enough to start selling books overseas you will need to become more familiar with double taxation and certificates of residence than you ever wanted to. And I'm fairly sure that H. P. Lovecraft got his inspiration for the Necronomicon after trying to get his head around a bilingual English/Japanese application form for exemption from reverse double taxation (translated from the original Japanese by someone for whom English was not their first language — but Japanese corporate tax law was).
Different countries have different prevailing sales channels. As I noted earlier, the UK has no mass market paperbacks any more (although the C format size paperback is still often misleadingly called "mass market"). France has its own anomalies. Large format paperbacks prevail in the high street, but there are also book clubs with enormous clout — when my French publisher sold book club rights to one of my novels, I was astonished to get a royalty check about five times the size of the corresponding one from SFBC in the United States. (Not because SFBC did a bad job, but because the French book club sales channel is their equivalent of the mass market, in terms of sheer volume.)
And different markets consume different amounts of different sub-genres. I have only a confused mosaic of impressions to share, because I can only describe my own experiences in translation: but the French market seems to be particularly big on Lovecraftian horror and fantasy, Germany goes for hard SF in a big way, Italy is a pretty small market, mostly for fantasy (and with some odd political overtones — fantasy, I'm told by a friendly Italian translator, is associated with the neofascist right), Spain is even smaller, to my great surprise both Russia and China pay respectable (if small) advances, in Japan hardcover publication is something of an honour reserved for high sellers, and so on.
I mentioned that my B&C advances were around 40% the size of my North American book advances. How big is the rest of the world? The answer is, "individually, not very — but it adds up". After some years of diligent selling, the advances against royalties for translations of "Singularity Sky" stacked up and in total matched the North American book advance. Of these, the French, German, and Japanese advances combined to make about 75%; the rest ... I'm probably not going to surprise you if I say that the Romanian and Bulgarian advances were not terribly large.
In a previous CMAP I mentioned Tobias Buckell's survey of SF/F author's book advances, which indicated that median advances for mid-career midlist SF authors were around $12,500 per book, or $15,000 for fantasy authors. It should be obvious that this isn't enough for an adult to live on, unless they're churning out 3-4 books a year or have a working partner or a private income. However, if they're canny and sell their rights in separate tranches, your nominal $15,000 advance for US rights is augmented by another $8000 for B&C rights, and then, over time, another $12-16,000 for the rest of the world in translation. $40,000 in advances for a book is enough to make a living, although you're never going to be rich and you've got to write more than one book a year if you're going to be comfortable.
The point to take away from this essay is: if you're an author and you rely on your North American rights, you'll be on the bread line. To actually earn a living, you really need to exploit other territorial and language rights.