I was just thinking about marketing and public relations, since I sometimes work on those types of projects and hear different kinds of conversations about it going on around me, especially when I'm in a cafe.
There aren't many books that every type of person will buy, unless it's fiction that appeals to a wide variety of people and has characters that represent different backgrounds and genders. If it's non-fiction, perhaps a celebrity will cast a large net over potential readers, but in other cases, there aren't many non-fiction books that can be huge sellers in a large market.
I love buying and reading foreign-language books (in addition to magazines). A popular publisher among people who are studying Japanese is
ALC. The most recent book I bought was
どんな時どう使う日本語表現文型500 [Donna toki dou tsukau nihongo hyogen bunkei] or 500 Essential Japanese Expressions (the English subtitle), which was published by them. And they seem to have a corner on the Japanese Language Proficiency Test market, since they used to publish the
Nihongo Journal and have released even more books on learning Japanese since quitting the magazine. But what also helps their marketing is their
site that has excellent dictionaries and other help, including audio files.
They don't have to do that--they can just publish their books and relax. But it's that extra service that they provide that makes people like me appreciate them, which helps when I'm deciding on a Japanese book to buy.
I think a cool concept is offering a free book or mini-book online.
Seth Godin posted a free e-book online while it was also available in print. Incredibly, he sold tens of thousands of copies of that book, Unleashing the Idea Virus, as a result (now it's only being
sold). Even though the free book isn't at his site anymore, you can get it at a
music promotion site and get other free books there as well. His book wasn't about music, and neither are some of the others, but those look helpful for any kind of marketing.
Offering a book for free is a good idea, I think, especially if someone has a "following" and/or a big media presence.