However, Spanish speakers and readers live throughout the United States and have increasingly shown that the market is national, not just regional. There are various types of titles that do well in the Spanish-language market. Stories that feature Hispanic protagonists, or that deal with aspects of Hispanic culture, are obvious choices that would appeal to this market. These include books written by Hispanic authors living in the US and those living in Latin America and Spain. Books that are very popular in English and that have become classics would be welcome in Spanish-language editions.
Good literature is universal.
Many publishers have had success with translations of their most popular titles. Many teachers, librarians, and book buyers are monolingual and are happy to buy titles that they know are tried and true. The decision to publish in hardcover or in paperback is arrived at through virtually the same process for a Spanish-language book as for one in English. These questions are as relevant in Spanish as they are in English. It may be better to wait to publish a hardcover Spanish edition until you see how well the English-language edition is selling.